Bug #275047 - Split _emerge/__init__.py into smaller pieces (part 5).

Thanks to Sebastian Mingramm (few) <s.mingramm@gmx.de> for this patch.

svn path=/main/trunk/; revision=13672

9 files changed, 6845 insertions, 6734 deletions

diff --git a/pym/_emerge/Scheduler.py b/pym/_emerge/Scheduler.py
new file mode 100644
index 000000000..7cf71343a
--- /dev/null
+++ b/pym/_emerge/Scheduler.py
@@ -0,0 +1,1641 @@
+import logging
+import os
+import sys
+import textwrap
+import time
+import weakref
+from itertools import izip
+
+try:
+	import portage
+except ImportError:
+	from os import path as osp
+	sys.path.insert(0, osp.join(osp.dirname(osp.dirname(osp.realpath(__file__))), "pym"))
+	import portage
+
+from portage.cache.mappings import slot_dict_class
+from portage.elog.messages import eerror
+from portage.output import colorize, create_color_func, darkgreen, red
+bad = create_color_func("BAD")
+from portage.sets.base import InternalPackageSet
+from portage.util import writemsg, writemsg_level
+
+from _emerge.BinpkgPrefetcher import BinpkgPrefetcher
+from _emerge.Blocker import Blocker
+from _emerge.BlockerDB import BlockerDB
+from _emerge.clear_caches import clear_caches
+from _emerge.create_depgraph_params import create_depgraph_params
+from _emerge.create_world_atom import create_world_atom
+from _emerge.DepPriority import DepPriority
+from _emerge.EbuildFetcher import EbuildFetcher
+from _emerge.EbuildPhase import EbuildPhase
+from _emerge.emergelog import emergelog, _emerge_log_dir
+from _emerge._find_deep_system_runtime_deps import _find_deep_system_runtime_deps
+from _emerge._flush_elog_mod_echo import _flush_elog_mod_echo
+from _emerge.JobStatusDisplay import JobStatusDisplay
+from _emerge.MergeListItem import MergeListItem
+from _emerge.Package import Package
+from _emerge.PackageMerge import PackageMerge
+from _emerge.PollScheduler import PollScheduler
+from _emerge.RootConfig import RootConfig
+from _emerge.SlotObject import SlotObject
+from _emerge.SequentialTaskQueue import SequentialTaskQueue
+from _emerge.show_invalid_depstring_notice import show_invalid_depstring_notice
+
+import portage.proxy.lazyimport
+import portage.proxy as proxy
+proxy.lazyimport.lazyimport(globals(),
+	'_emerge.depgraph:depgraph',
+)
+
+class Scheduler(PollScheduler):
+
+	_opts_ignore_blockers = \
+		frozenset(["--buildpkgonly",
+		"--fetchonly", "--fetch-all-uri",
+		"--nodeps", "--pretend"])
+
+	_opts_no_background = \
+		frozenset(["--pretend",
+		"--fetchonly", "--fetch-all-uri"])
+
+	_opts_no_restart = frozenset(["--buildpkgonly",
+		"--fetchonly", "--fetch-all-uri", "--pretend"])
+
+	_bad_resume_opts = set(["--ask", "--changelog",
+		"--resume", "--skipfirst"])
+
+	_fetch_log = os.path.join(_emerge_log_dir, 'emerge-fetch.log')
+
+	class _iface_class(SlotObject):
+		__slots__ = ("dblinkEbuildPhase", "dblinkDisplayMerge",
+			"dblinkElog", "dblinkEmergeLog", "fetch", "register", "schedule",
+			"scheduleSetup", "scheduleUnpack", "scheduleYield",
+			"unregister")
+
+	class _fetch_iface_class(SlotObject):
+		__slots__ = ("log_file", "schedule")
+
+	_task_queues_class = slot_dict_class(
+		("merge", "jobs", "fetch", "unpack"), prefix="")
+
+	class _build_opts_class(SlotObject):
+		__slots__ = ("buildpkg", "buildpkgonly",
+			"fetch_all_uri", "fetchonly", "pretend")
+
+	class _binpkg_opts_class(SlotObject):
+		__slots__ = ("fetchonly", "getbinpkg", "pretend")
+
+	class _pkg_count_class(SlotObject):
+		__slots__ = ("curval", "maxval")
+
+	class _emerge_log_class(SlotObject):
+		__slots__ = ("xterm_titles",)
+
+		def log(self, *pargs, **kwargs):
+			if not self.xterm_titles:
+				# Avoid interference with the scheduler's status display.
+				kwargs.pop("short_msg", None)
+			emergelog(self.xterm_titles, *pargs, **kwargs)
+
+	class _failed_pkg(SlotObject):
+		__slots__ = ("build_dir", "build_log", "pkg", "returncode")
+
+	class _ConfigPool(object):
+		"""Interface for a task to temporarily allocate a config
+		instance from a pool. This allows a task to be constructed
+		long before the config instance actually becomes needed, like
+		when prefetchers are constructed for the whole merge list."""
+		__slots__ = ("_root", "_allocate", "_deallocate")
+		def __init__(self, root, allocate, deallocate):
+			self._root = root
+			self._allocate = allocate
+			self._deallocate = deallocate
+		def allocate(self):
+			return self._allocate(self._root)
+		def deallocate(self, settings):
+			self._deallocate(settings)
+
+	class _unknown_internal_error(portage.exception.PortageException):
+		"""
+		Used internally to terminate scheduling. The specific reason for
+		the failure should have been dumped to stderr.
+		"""
+		def __init__(self, value=""):
+			portage.exception.PortageException.__init__(self, value)
+
+	def __init__(self, settings, trees, mtimedb, myopts,
+		spinner, mergelist, favorites, digraph):
+		PollScheduler.__init__(self)
+		self.settings = settings
+		self.target_root = settings["ROOT"]
+		self.trees = trees
+		self.myopts = myopts
+		self._spinner = spinner
+		self._mtimedb = mtimedb
+		self._mergelist = mergelist
+		self._favorites = favorites
+		self._args_set = InternalPackageSet(favorites)
+		self._build_opts = self._build_opts_class()
+		for k in self._build_opts.__slots__:
+			setattr(self._build_opts, k, "--" + k.replace("_", "-") in myopts)
+		self._binpkg_opts = self._binpkg_opts_class()
+		for k in self._binpkg_opts.__slots__:
+			setattr(self._binpkg_opts, k, "--" + k.replace("_", "-") in myopts)
+
+		self.curval = 0
+		self._logger = self._emerge_log_class()
+		self._task_queues = self._task_queues_class()
+		for k in self._task_queues.allowed_keys:
+			setattr(self._task_queues, k,
+				SequentialTaskQueue())
+
+		# Holds merges that will wait to be executed when no builds are
+		# executing. This is useful for system packages since dependencies
+		# on system packages are frequently unspecified.
+		self._merge_wait_queue = []
+		# Holds merges that have been transfered from the merge_wait_queue to
+		# the actual merge queue. They are removed from this list upon
+		# completion. Other packages can start building only when this list is
+		# empty.
+		self._merge_wait_scheduled = []
+
+		# Holds system packages and their deep runtime dependencies. Before
+		# being merged, these packages go to merge_wait_queue, to be merged
+		# when no other packages are building.
+		self._deep_system_deps = set()
+
+		# Holds packages to merge which will satisfy currently unsatisfied
+		# deep runtime dependencies of system packages. If this is not empty
+		# then no parallel builds will be spawned until it is empty. This
+		# minimizes the possibility that a build will fail due to the system
+		# being in a fragile state. For example, see bug #259954.
+		self._unsatisfied_system_deps = set()
+
+		self._status_display = JobStatusDisplay(
+			xterm_titles=('notitles' not in settings.features))
+		self._max_load = myopts.get("--load-average")
+		max_jobs = myopts.get("--jobs")
+		if max_jobs is None:
+			max_jobs = 1
+		self._set_max_jobs(max_jobs)
+
+		# The root where the currently running
+		# portage instance is installed.
+		self._running_root = trees["/"]["root_config"]
+		self.edebug = 0
+		if settings.get("PORTAGE_DEBUG", "") == "1":
+			self.edebug = 1
+		self.pkgsettings = {}
+		self._config_pool = {}
+		self._blocker_db = {}
+		for root in trees:
+			self._config_pool[root] = []
+			self._blocker_db[root] = BlockerDB(trees[root]["root_config"])
+
+		fetch_iface = self._fetch_iface_class(log_file=self._fetch_log,
+			schedule=self._schedule_fetch)
+		self._sched_iface = self._iface_class(
+			dblinkEbuildPhase=self._dblink_ebuild_phase,
+			dblinkDisplayMerge=self._dblink_display_merge,
+			dblinkElog=self._dblink_elog,
+			dblinkEmergeLog=self._dblink_emerge_log,
+			fetch=fetch_iface, register=self._register,
+			schedule=self._schedule_wait,
+			scheduleSetup=self._schedule_setup,
+			scheduleUnpack=self._schedule_unpack,
+			scheduleYield=self._schedule_yield,
+			unregister=self._unregister)
+
+		self._prefetchers = weakref.WeakValueDictionary()
+		self._pkg_queue = []
+		self._completed_tasks = set()
+
+		self._failed_pkgs = []
+		self._failed_pkgs_all = []
+		self._failed_pkgs_die_msgs = []
+		self._post_mod_echo_msgs = []
+		self._parallel_fetch = False
+		merge_count = len([x for x in mergelist \
+			if isinstance(x, Package) and x.operation == "merge"])
+		self._pkg_count = self._pkg_count_class(
+			curval=0, maxval=merge_count)
+		self._status_display.maxval = self._pkg_count.maxval
+
+		# The load average takes some time to respond when new
+		# jobs are added, so we need to limit the rate of adding
+		# new jobs.
+		self._job_delay_max = 10
+		self._job_delay_factor = 1.0
+		self._job_delay_exp = 1.5
+		self._previous_job_start_time = None
+
+		self._set_digraph(digraph)
+
+		# This is used to memoize the _choose_pkg() result when
+		# no packages can be chosen until one of the existing
+		# jobs completes.
+		self._choose_pkg_return_early = False
+
+		features = self.settings.features
+		if "parallel-fetch" in features and \
+			not ("--pretend" in self.myopts or \
+			"--fetch-all-uri" in self.myopts or \
+			"--fetchonly" in self.myopts):
+			if "distlocks" not in features:
+				portage.writemsg(red("!!!")+"\n", noiselevel=-1)
+				portage.writemsg(red("!!!")+" parallel-fetching " + \
+					"requires the distlocks feature enabled"+"\n",
+					noiselevel=-1)
+				portage.writemsg(red("!!!")+" you have it disabled, " + \
+					"thus parallel-fetching is being disabled"+"\n",
+					noiselevel=-1)
+				portage.writemsg(red("!!!")+"\n", noiselevel=-1)
+			elif len(mergelist) > 1:
+				self._parallel_fetch = True
+
+		if self._parallel_fetch:
+				# clear out existing fetch log if it exists
+				try:
+					open(self._fetch_log, 'w')
+				except EnvironmentError:
+					pass
+
+		self._running_portage = None
+		portage_match = self._running_root.trees["vartree"].dbapi.match(
+			portage.const.PORTAGE_PACKAGE_ATOM)
+		if portage_match:
+			cpv = portage_match.pop()
+			self._running_portage = self._pkg(cpv, "installed",
+				self._running_root, installed=True)
+
+	def _poll(self, timeout=None):
+		self._schedule()
+		PollScheduler._poll(self, timeout=timeout)
+
+	def _set_max_jobs(self, max_jobs):
+		self._max_jobs = max_jobs
+		self._task_queues.jobs.max_jobs = max_jobs
+
+	def _background_mode(self):
+		"""
+		Check if background mode is enabled and adjust states as necessary.
+
+		@rtype: bool
+		@returns: True if background mode is enabled, False otherwise.
+		"""
+		background = (self._max_jobs is True or \
+			self._max_jobs > 1 or "--quiet" in self.myopts) and \
+			not bool(self._opts_no_background.intersection(self.myopts))
+
+		if background:
+			interactive_tasks = self._get_interactive_tasks()
+			if interactive_tasks:
+				background = False
+				writemsg_level(">>> Sending package output to stdio due " + \
+					"to interactive package(s):\n",
+					level=logging.INFO, noiselevel=-1)
+				msg = [""]
+				for pkg in interactive_tasks:
+					pkg_str = "  " + colorize("INFORM", str(pkg.cpv))
+					if pkg.root != "/":
+						pkg_str += " for " + pkg.root
+					msg.append(pkg_str)
+				msg.append("")
+				writemsg_level("".join("%s\n" % (l,) for l in msg),
+					level=logging.INFO, noiselevel=-1)
+				if self._max_jobs is True or self._max_jobs > 1:
+					self._set_max_jobs(1)
+					writemsg_level(">>> Setting --jobs=1 due " + \
+						"to the above interactive package(s)\n",
+						level=logging.INFO, noiselevel=-1)
+
+		self._status_display.quiet = \
+			not background or \
+			("--quiet" in self.myopts and \
+			"--verbose" not in self.myopts)
+
+		self._logger.xterm_titles = \
+			"notitles" not in self.settings.features and \
+			self._status_display.quiet
+
+		return background
+
+	def _get_interactive_tasks(self):
+		from portage import flatten
+		from portage.dep import use_reduce, paren_reduce
+		interactive_tasks = []
+		for task in self._mergelist:
+			if not (isinstance(task, Package) and \
+				task.operation == "merge"):
+				continue
+			try:
+				properties = flatten(use_reduce(paren_reduce(
+					task.metadata["PROPERTIES"]), uselist=task.use.enabled))
+			except portage.exception.InvalidDependString, e:
+				show_invalid_depstring_notice(task,
+					task.metadata["PROPERTIES"], str(e))
+				raise self._unknown_internal_error()
+			if "interactive" in properties:
+				interactive_tasks.append(task)
+		return interactive_tasks
+
+	def _set_digraph(self, digraph):
+		if "--nodeps" in self.myopts or \
+			(self._max_jobs is not True and self._max_jobs < 2):
+			# save some memory
+			self._digraph = None
+			return
+
+		self._digraph = digraph
+		self._find_system_deps()
+		self._prune_digraph()
+		self._prevent_builddir_collisions()
+
+	def _find_system_deps(self):
+		"""
+		Find system packages and their deep runtime dependencies. Before being
+		merged, these packages go to merge_wait_queue, to be merged when no
+		other packages are building.
+		"""
+		deep_system_deps = self._deep_system_deps
+		deep_system_deps.clear()
+		deep_system_deps.update(
+			_find_deep_system_runtime_deps(self._digraph))
+		deep_system_deps.difference_update([pkg for pkg in \
+			deep_system_deps if pkg.operation != "merge"])
+
+	def _prune_digraph(self):
+		"""
+		Prune any root nodes that are irrelevant.
+		"""
+
+		graph = self._digraph
+		completed_tasks = self._completed_tasks
+		removed_nodes = set()
+		while True:
+			for node in graph.root_nodes():
+				if not isinstance(node, Package) or \
+					(node.installed and node.operation == "nomerge") or \
+					node.onlydeps or \
+					node in completed_tasks:
+					removed_nodes.add(node)
+			if removed_nodes:
+				graph.difference_update(removed_nodes)
+			if not removed_nodes:
+				break
+			removed_nodes.clear()
+
+	def _prevent_builddir_collisions(self):
+		"""
+		When building stages, sometimes the same exact cpv needs to be merged
+		to both $ROOTs. Add edges to the digraph in order to avoid collisions
+		in the builddir. Currently, normal file locks would be inappropriate
+		for this purpose since emerge holds all of it's build dir locks from
+		the main process.
+		"""
+		cpv_map = {}
+		for pkg in self._mergelist:
+			if not isinstance(pkg, Package):
+				# a satisfied blocker
+				continue
+			if pkg.installed:
+				continue
+			if pkg.cpv not in cpv_map:
+				cpv_map[pkg.cpv] = [pkg]
+				continue
+			for earlier_pkg in cpv_map[pkg.cpv]:
+				self._digraph.add(earlier_pkg, pkg,
+					priority=DepPriority(buildtime=True))
+			cpv_map[pkg.cpv].append(pkg)
+
+	class _pkg_failure(portage.exception.PortageException):
+		"""
+		An instance of this class is raised by unmerge() when
+		an uninstallation fails.
+		"""
+		status = 1
+		def __init__(self, *pargs):
+			portage.exception.PortageException.__init__(self, pargs)
+			if pargs:
+				self.status = pargs[0]
+
+	def _schedule_fetch(self, fetcher):
+		"""
+		Schedule a fetcher on the fetch queue, in order to
+		serialize access to the fetch log.
+		"""
+		self._task_queues.fetch.addFront(fetcher)
+
+	def _schedule_setup(self, setup_phase):
+		"""
+		Schedule a setup phase on the merge queue, in order to
+		serialize unsandboxed access to the live filesystem.
+		"""
+		self._task_queues.merge.addFront(setup_phase)
+		self._schedule()
+
+	def _schedule_unpack(self, unpack_phase):
+		"""
+		Schedule an unpack phase on the unpack queue, in order
+		to serialize $DISTDIR access for live ebuilds.
+		"""
+		self._task_queues.unpack.add(unpack_phase)
+
+	def _find_blockers(self, new_pkg):
+		"""
+		Returns a callable which should be called only when
+		the vdb lock has been acquired.
+		"""
+		def get_blockers():
+			return self._find_blockers_with_lock(new_pkg, acquire_lock=0)
+		return get_blockers
+
+	def _find_blockers_with_lock(self, new_pkg, acquire_lock=0):
+		if self._opts_ignore_blockers.intersection(self.myopts):
+			return None
+
+		# Call gc.collect() here to avoid heap overflow that
+		# triggers 'Cannot allocate memory' errors (reported
+		# with python-2.5).
+		import gc
+		gc.collect()
+
+		blocker_db = self._blocker_db[new_pkg.root]
+
+		blocker_dblinks = []
+		for blocking_pkg in blocker_db.findInstalledBlockers(
+			new_pkg, acquire_lock=acquire_lock):
+			if new_pkg.slot_atom == blocking_pkg.slot_atom:
+				continue
+			if new_pkg.cpv == blocking_pkg.cpv:
+				continue
+			blocker_dblinks.append(portage.dblink(
+				blocking_pkg.category, blocking_pkg.pf, blocking_pkg.root,
+				self.pkgsettings[blocking_pkg.root], treetype="vartree",
+				vartree=self.trees[blocking_pkg.root]["vartree"]))
+
+		gc.collect()
+
+		return blocker_dblinks
+
+	def _dblink_pkg(self, pkg_dblink):
+		cpv = pkg_dblink.mycpv
+		type_name = RootConfig.tree_pkg_map[pkg_dblink.treetype]
+		root_config = self.trees[pkg_dblink.myroot]["root_config"]
+		installed = type_name == "installed"
+		return self._pkg(cpv, type_name, root_config, installed=installed)
+
+	def _append_to_log_path(self, log_path, msg):
+		f = open(log_path, 'a')
+		try:
+			f.write(msg)
+		finally:
+			f.close()
+
+	def _dblink_elog(self, pkg_dblink, phase, func, msgs):
+
+		log_path = pkg_dblink.settings.get("PORTAGE_LOG_FILE")
+		log_file = None
+		out = sys.stdout
+		background = self._background
+
+		if background and log_path is not None:
+			log_file = open(log_path, 'a')
+			out = log_file
+
+		try:
+			for msg in msgs:
+				func(msg, phase=phase, key=pkg_dblink.mycpv, out=out)
+		finally:
+			if log_file is not None:
+				log_file.close()
+
+	def _dblink_emerge_log(self, msg):
+		self._logger.log(msg)
+
+	def _dblink_display_merge(self, pkg_dblink, msg, level=0, noiselevel=0):
+		log_path = pkg_dblink.settings.get("PORTAGE_LOG_FILE")
+		background = self._background
+
+		if log_path is None:
+			if not (background and level < logging.WARN):
+				portage.util.writemsg_level(msg,
+					level=level, noiselevel=noiselevel)
+		else:
+			if not background:
+				portage.util.writemsg_level(msg,
+					level=level, noiselevel=noiselevel)
+			self._append_to_log_path(log_path, msg)
+
+	def _dblink_ebuild_phase(self,
+		pkg_dblink, pkg_dbapi, ebuild_path, phase):
+		"""
+		Using this callback for merge phases allows the scheduler
+		to run while these phases execute asynchronously, and allows
+		the scheduler control output handling.
+		"""
+
+		scheduler = self._sched_iface
+		settings = pkg_dblink.settings
+		pkg = self._dblink_pkg(pkg_dblink)
+		background = self._background
+		log_path = settings.get("PORTAGE_LOG_FILE")
+
+		ebuild_phase = EbuildPhase(background=background,
+			pkg=pkg, phase=phase, scheduler=scheduler,
+			settings=settings, tree=pkg_dblink.treetype)
+		ebuild_phase.start()
+		ebuild_phase.wait()
+
+		return ebuild_phase.returncode
+
+	def _generate_digests(self):
+		"""
+		Generate digests if necessary for --digests or FEATURES=digest.
+		In order to avoid interference, this must done before parallel
+		tasks are started.
+		"""
+
+		if '--fetchonly' in self.myopts:
+			return os.EX_OK
+
+		digest = '--digest' in self.myopts
+		if not digest:
+			for pkgsettings in self.pkgsettings.itervalues():
+				if 'digest' in pkgsettings.features:
+					digest = True
+					break
+
+		if not digest:
+			return os.EX_OK
+
+		for x in self._mergelist:
+			if not isinstance(x, Package) or \
+				x.type_name != 'ebuild' or \
+				x.operation != 'merge':
+				continue
+			pkgsettings = self.pkgsettings[x.root]
+			if '--digest' not in self.myopts and \
+				'digest' not in pkgsettings.features:
+				continue
+			portdb = x.root_config.trees['porttree'].dbapi
+			ebuild_path = portdb.findname(x.cpv)
+			if not ebuild_path:
+				writemsg_level(
+					"!!! Could not locate ebuild for '%s'.\n" \
+					% x.cpv, level=logging.ERROR, noiselevel=-1)
+				return 1
+			pkgsettings['O'] = os.path.dirname(ebuild_path)
+			if not portage.digestgen([], pkgsettings, myportdb=portdb):
+				writemsg_level(
+					"!!! Unable to generate manifest for '%s'.\n" \
+					% x.cpv, level=logging.ERROR, noiselevel=-1)
+				return 1
+
+		return os.EX_OK
+
+	def _check_manifests(self):
+		# Verify all the manifests now so that the user is notified of failure
+		# as soon as possible.
+		if "strict" not in self.settings.features or \
+			"--fetchonly" in self.myopts or \
+			"--fetch-all-uri" in self.myopts:
+			return os.EX_OK
+
+		shown_verifying_msg = False
+		quiet_settings = {}
+		for myroot, pkgsettings in self.pkgsettings.iteritems():
+			quiet_config = portage.config(clone=pkgsettings)
+			quiet_config["PORTAGE_QUIET"] = "1"
+			quiet_config.backup_changes("PORTAGE_QUIET")
+			quiet_settings[myroot] = quiet_config
+			del quiet_config
+
+		for x in self._mergelist:
+			if not isinstance(x, Package) or \
+				x.type_name != "ebuild":
+				continue
+
+			if not shown_verifying_msg:
+				shown_verifying_msg = True
+				self._status_msg("Verifying ebuild manifests")
+
+			root_config = x.root_config
+			portdb = root_config.trees["porttree"].dbapi
+			quiet_config = quiet_settings[root_config.root]
+			quiet_config["O"] = os.path.dirname(portdb.findname(x.cpv))
+			if not portage.digestcheck([], quiet_config, strict=True):
+				return 1
+
+		return os.EX_OK
+
+	def _add_prefetchers(self):
+
+		if not self._parallel_fetch:
+			return
+
+		if self._parallel_fetch:
+			self._status_msg("Starting parallel fetch")
+
+			prefetchers = self._prefetchers
+			getbinpkg = "--getbinpkg" in self.myopts
+
+			# In order to avoid "waiting for lock" messages
+			# at the beginning, which annoy users, never
+			# spawn a prefetcher for the first package.
+			for pkg in self._mergelist[1:]:
+				prefetcher = self._create_prefetcher(pkg)
+				if prefetcher is not None:
+					self._task_queues.fetch.add(prefetcher)
+					prefetchers[pkg] = prefetcher
+
+	def _create_prefetcher(self, pkg):
+		"""
+		@return: a prefetcher, or None if not applicable
+		"""
+		prefetcher = None
+
+		if not isinstance(pkg, Package):
+			pass
+
+		elif pkg.type_name == "ebuild":
+
+			prefetcher = EbuildFetcher(background=True,
+				config_pool=self._ConfigPool(pkg.root,
+				self._allocate_config, self._deallocate_config),
+				fetchonly=1, logfile=self._fetch_log,
+				pkg=pkg, prefetch=True, scheduler=self._sched_iface)
+
+		elif pkg.type_name == "binary" and \
+			"--getbinpkg" in self.myopts and \
+			pkg.root_config.trees["bintree"].isremote(pkg.cpv):
+
+			prefetcher = BinpkgPrefetcher(background=True,
+				pkg=pkg, scheduler=self._sched_iface)
+
+		return prefetcher
+
+	def _is_restart_scheduled(self):
+		"""
+		Check if the merge list contains a replacement
+		for the current running instance, that will result
+		in restart after merge.
+		@rtype: bool
+		@returns: True if a restart is scheduled, False otherwise.
+		"""
+		if self._opts_no_restart.intersection(self.myopts):
+			return False
+
+		mergelist = self._mergelist
+
+		for i, pkg in enumerate(mergelist):
+			if self._is_restart_necessary(pkg) and \
+				i != len(mergelist) - 1:
+				return True
+
+		return False
+
+	def _is_restart_necessary(self, pkg):
+		"""
+		@return: True if merging the given package
+			requires restart, False otherwise.
+		"""
+
+		# Figure out if we need a restart.
+		if pkg.root == self._running_root.root and \
+			portage.match_from_list(
+			portage.const.PORTAGE_PACKAGE_ATOM, [pkg]):
+			if self._running_portage:
+				return pkg.cpv != self._running_portage.cpv
+			return True
+		return False
+
+	def _restart_if_necessary(self, pkg):
+		"""
+		Use execv() to restart emerge. This happens
+		if portage upgrades itself and there are
+		remaining packages in the list.
+		"""
+
+		if self._opts_no_restart.intersection(self.myopts):
+			return
+
+		if not self._is_restart_necessary(pkg):
+			return
+
+		if pkg == self._mergelist[-1]:
+			return
+
+		self._main_loop_cleanup()
+
+		logger = self._logger
+		pkg_count = self._pkg_count
+		mtimedb = self._mtimedb
+		bad_resume_opts = self._bad_resume_opts
+
+		logger.log(" ::: completed emerge (%s of %s) %s to %s" % \
+			(pkg_count.curval, pkg_count.maxval, pkg.cpv, pkg.root))
+
+		logger.log(" *** RESTARTING " + \
+			"emerge via exec() after change of " + \
+			"portage version.")
+
+		mtimedb["resume"]["mergelist"].remove(list(pkg))
+		mtimedb.commit()
+		portage.run_exitfuncs()
+		mynewargv = [sys.argv[0], "--resume"]
+		resume_opts = self.myopts.copy()
+		# For automatic resume, we need to prevent
+		# any of bad_resume_opts from leaking in
+		# via EMERGE_DEFAULT_OPTS.
+		resume_opts["--ignore-default-opts"] = True
+		for myopt, myarg in resume_opts.iteritems():
+			if myopt not in bad_resume_opts:
+				if myarg is True:
+					mynewargv.append(myopt)
+				else:
+					mynewargv.append(myopt +"="+ str(myarg))
+		# priority only needs to be adjusted on the first run
+		os.environ["PORTAGE_NICENESS"] = "0"
+		os.execv(mynewargv[0], mynewargv)
+
+	def merge(self):
+
+		if "--resume" in self.myopts:
+			# We're resuming.
+			portage.writemsg_stdout(
+				colorize("GOOD", "*** Resuming merge...\n"), noiselevel=-1)
+			self._logger.log(" *** Resuming merge...")
+
+		self._save_resume_list()
+
+		try:
+			self._background = self._background_mode()
+		except self._unknown_internal_error:
+			return 1
+
+		for root in self.trees:
+			root_config = self.trees[root]["root_config"]
+
+			# Even for --pretend --fetch mode, PORTAGE_TMPDIR is required
+			# since it might spawn pkg_nofetch which requires PORTAGE_BUILDDIR
+			# for ensuring sane $PWD (bug #239560) and storing elog messages.
+			tmpdir = root_config.settings.get("PORTAGE_TMPDIR", "")
+			if not tmpdir or not os.path.isdir(tmpdir):
+				msg = "The directory specified in your " + \
+					"PORTAGE_TMPDIR variable, '%s', " % tmpdir + \
+				"does not exist. Please create this " + \
+				"directory or correct your PORTAGE_TMPDIR setting."
+				msg = textwrap.wrap(msg, 70)
+				out = portage.output.EOutput()
+				for l in msg:
+					out.eerror(l)
+				return 1
+
+			if self._background:
+				root_config.settings.unlock()
+				root_config.settings["PORTAGE_BACKGROUND"] = "1"
+				root_config.settings.backup_changes("PORTAGE_BACKGROUND")
+				root_config.settings.lock()
+
+			self.pkgsettings[root] = portage.config(
+				clone=root_config.settings)
+
+		rval = self._generate_digests()
+		if rval != os.EX_OK:
+			return rval
+
+		rval = self._check_manifests()
+		if rval != os.EX_OK:
+			return rval
+
+		keep_going = "--keep-going" in self.myopts
+		fetchonly = self._build_opts.fetchonly
+		mtimedb = self._mtimedb
+		failed_pkgs = self._failed_pkgs
+
+		while True:
+			rval = self._merge()
+			if rval == os.EX_OK or fetchonly or not keep_going:
+				break
+			if "resume" not in mtimedb:
+				break
+			mergelist = self._mtimedb["resume"].get("mergelist")
+			if not mergelist:
+				break
+
+			if not failed_pkgs:
+				break
+
+			for failed_pkg in failed_pkgs:
+				mergelist.remove(list(failed_pkg.pkg))
+
+			self._failed_pkgs_all.extend(failed_pkgs)
+			del failed_pkgs[:]
+
+			if not mergelist:
+				break
+
+			if not self._calc_resume_list():
+				break
+
+			clear_caches(self.trees)
+			if not self._mergelist:
+				break
+
+			self._save_resume_list()
+			self._pkg_count.curval = 0
+			self._pkg_count.maxval = len([x for x in self._mergelist \
+				if isinstance(x, Package) and x.operation == "merge"])
+			self._status_display.maxval = self._pkg_count.maxval
+
+		self._logger.log(" *** Finished. Cleaning up...")
+
+		if failed_pkgs:
+			self._failed_pkgs_all.extend(failed_pkgs)
+			del failed_pkgs[:]
+
+		background = self._background
+		failure_log_shown = False
+		if background and len(self._failed_pkgs_all) == 1:
+			# If only one package failed then just show it's
+			# whole log for easy viewing.
+			failed_pkg = self._failed_pkgs_all[-1]
+			build_dir = failed_pkg.build_dir
+			log_file = None
+
+			log_paths = [failed_pkg.build_log]
+
+			log_path = self._locate_failure_log(failed_pkg)
+			if log_path is not None:
+				try:
+					log_file = open(log_path)
+				except IOError:
+					pass
+
+			if log_file is not None:
+				try:
+					for line in log_file:
+						writemsg_level(line, noiselevel=-1)
+				finally:
+					log_file.close()
+				failure_log_shown = True
+
+		# Dump mod_echo output now since it tends to flood the terminal.
+		# This allows us to avoid having more important output, generated
+		# later, from being swept away by the mod_echo output.
+		mod_echo_output =  _flush_elog_mod_echo()
+
+		if background and not failure_log_shown and \
+			self._failed_pkgs_all and \
+			self._failed_pkgs_die_msgs and \
+			not mod_echo_output:
+
+			printer = portage.output.EOutput()
+			for mysettings, key, logentries in self._failed_pkgs_die_msgs:
+				root_msg = ""
+				if mysettings["ROOT"] != "/":
+					root_msg = " merged to %s" % mysettings["ROOT"]
+				print
+				printer.einfo("Error messages for package %s%s:" % \
+					(colorize("INFORM", key), root_msg))
+				print
+				for phase in portage.const.EBUILD_PHASES:
+					if phase not in logentries:
+						continue
+					for msgtype, msgcontent in logentries[phase]:
+						if isinstance(msgcontent, basestring):
+							msgcontent = [msgcontent]
+						for line in msgcontent:
+							printer.eerror(line.strip("\n"))
+
+		if self._post_mod_echo_msgs:
+			for msg in self._post_mod_echo_msgs:
+				msg()
+
+		if len(self._failed_pkgs_all) > 1 or \
+			(self._failed_pkgs_all and "--keep-going" in self.myopts):
+			if len(self._failed_pkgs_all) > 1:
+				msg = "The following %d packages have " % \
+					len(self._failed_pkgs_all) + \
+					"failed to build or install:"
+			else:
+				msg = "The following package has " + \
+					"failed to build or install:"
+			prefix = bad(" * ")
+			writemsg(prefix + "\n", noiselevel=-1)
+			from textwrap import wrap
+			for line in wrap(msg, 72):
+				writemsg("%s%s\n" % (prefix, line), noiselevel=-1)
+			writemsg(prefix + "\n", noiselevel=-1)
+			for failed_pkg in self._failed_pkgs_all:
+				writemsg("%s\t%s\n" % (prefix,
+					colorize("INFORM", str(failed_pkg.pkg))),
+					noiselevel=-1)
+			writemsg(prefix + "\n", noiselevel=-1)
+
+		return rval
+
+	def _elog_listener(self, mysettings, key, logentries, fulltext):
+		errors = portage.elog.filter_loglevels(logentries, ["ERROR"])
+		if errors:
+			self._failed_pkgs_die_msgs.append(
+				(mysettings, key, errors))
+
+	def _locate_failure_log(self, failed_pkg):
+
+		build_dir = failed_pkg.build_dir
+		log_file = None
+
+		log_paths = [failed_pkg.build_log]
+
+		for log_path in log_paths:
+			if not log_path:
+				continue
+
+			try:
+				log_size = os.stat(log_path).st_size
+			except OSError:
+				continue
+
+			if log_size == 0:
+				continue
+
+			return log_path
+
+		return None
+
+	def _add_packages(self):
+		pkg_queue = self._pkg_queue
+		for pkg in self._mergelist:
+			if isinstance(pkg, Package):
+				pkg_queue.append(pkg)
+			elif isinstance(pkg, Blocker):
+				pass
+
+	def _system_merge_started(self, merge):
+		"""
+		Add any unsatisfied runtime deps to self._unsatisfied_system_deps.
+		"""
+		graph = self._digraph
+		if graph is None:
+			return
+		pkg = merge.merge.pkg
+
+		# Skip this if $ROOT != / since it shouldn't matter if there
+		# are unsatisfied system runtime deps in this case.
+		if pkg.root != '/':
+			return
+
+		completed_tasks = self._completed_tasks
+		unsatisfied = self._unsatisfied_system_deps
+
+		def ignore_non_runtime_or_satisfied(priority):
+			"""
+			Ignore non-runtime and satisfied runtime priorities.
+			"""
+			if isinstance(priority, DepPriority) and \
+				not priority.satisfied and \
+				(priority.runtime or priority.runtime_post):
+				return False
+			return True
+
+		# When checking for unsatisfied runtime deps, only check
+		# direct deps since indirect deps are checked when the
+		# corresponding parent is merged.
+		for child in graph.child_nodes(pkg,
+			ignore_priority=ignore_non_runtime_or_satisfied):
+			if not isinstance(child, Package) or \
+				child.operation == 'uninstall':
+				continue
+			if child is pkg:
+				continue
+			if child.operation == 'merge' and \
+				child not in completed_tasks:
+				unsatisfied.add(child)
+
+	def _merge_wait_exit_handler(self, task):
+		self._merge_wait_scheduled.remove(task)
+		self._merge_exit(task)
+
+	def _merge_exit(self, merge):
+		self._do_merge_exit(merge)
+		self._deallocate_config(merge.merge.settings)
+		if merge.returncode == os.EX_OK and \
+			not merge.merge.pkg.installed:
+			self._status_display.curval += 1
+		self._status_display.merges = len(self._task_queues.merge)
+		self._schedule()
+
+	def _do_merge_exit(self, merge):
+		pkg = merge.merge.pkg
+		if merge.returncode != os.EX_OK:
+			settings = merge.merge.settings
+			build_dir = settings.get("PORTAGE_BUILDDIR")
+			build_log = settings.get("PORTAGE_LOG_FILE")
+
+			self._failed_pkgs.append(self._failed_pkg(
+				build_dir=build_dir, build_log=build_log,
+				pkg=pkg,
+				returncode=merge.returncode))
+			self._failed_pkg_msg(self._failed_pkgs[-1], "install", "to")
+
+			self._status_display.failed = len(self._failed_pkgs)
+			return
+
+		self._task_complete(pkg)
+		pkg_to_replace = merge.merge.pkg_to_replace
+		if pkg_to_replace is not None:
+			# When a package is replaced, mark it's uninstall
+			# task complete (if any).
+			uninst_hash_key = \
+				("installed", pkg.root, pkg_to_replace.cpv, "uninstall")
+			self._task_complete(uninst_hash_key)
+
+		if pkg.installed:
+			return
+
+		self._restart_if_necessary(pkg)
+
+		# Call mtimedb.commit() after each merge so that
+		# --resume still works after being interrupted
+		# by reboot, sigkill or similar.
+		mtimedb = self._mtimedb
+		mtimedb["resume"]["mergelist"].remove(list(pkg))
+		if not mtimedb["resume"]["mergelist"]:
+			del mtimedb["resume"]
+		mtimedb.commit()
+
+	def _build_exit(self, build):
+		if build.returncode == os.EX_OK:
+			self.curval += 1
+			merge = PackageMerge(merge=build)
+			if not build.build_opts.buildpkgonly and \
+				build.pkg in self._deep_system_deps:
+				# Since dependencies on system packages are frequently
+				# unspecified, merge them only when no builds are executing.
+				self._merge_wait_queue.append(merge)
+				merge.addStartListener(self._system_merge_started)
+			else:
+				merge.addExitListener(self._merge_exit)
+				self._task_queues.merge.add(merge)
+				self._status_display.merges = len(self._task_queues.merge)
+		else:
+			settings = build.settings
+			build_dir = settings.get("PORTAGE_BUILDDIR")
+			build_log = settings.get("PORTAGE_LOG_FILE")
+
+			self._failed_pkgs.append(self._failed_pkg(
+				build_dir=build_dir, build_log=build_log,
+				pkg=build.pkg,
+				returncode=build.returncode))
+			self._failed_pkg_msg(self._failed_pkgs[-1], "emerge", "for")
+
+			self._status_display.failed = len(self._failed_pkgs)
+			self._deallocate_config(build.settings)
+		self._jobs -= 1
+		self._status_display.running = self._jobs
+		self._schedule()
+
+	def _extract_exit(self, build):
+		self._build_exit(build)
+
+	def _task_complete(self, pkg):
+		self._completed_tasks.add(pkg)
+		self._unsatisfied_system_deps.discard(pkg)
+		self._choose_pkg_return_early = False
+
+	def _merge(self):
+
+		self._add_prefetchers()
+		self._add_packages()
+		pkg_queue = self._pkg_queue
+		failed_pkgs = self._failed_pkgs
+		portage.locks._quiet = self._background
+		portage.elog._emerge_elog_listener = self._elog_listener
+		rval = os.EX_OK
+
+		try:
+			self._main_loop()
+		finally:
+			self._main_loop_cleanup()
+			portage.locks._quiet = False
+			portage.elog._emerge_elog_listener = None
+			if failed_pkgs:
+				rval = failed_pkgs[-1].returncode
+
+		return rval
+
+	def _main_loop_cleanup(self):
+		del self._pkg_queue[:]
+		self._completed_tasks.clear()
+		self._deep_system_deps.clear()
+		self._unsatisfied_system_deps.clear()
+		self._choose_pkg_return_early = False
+		self._status_display.reset()
+		self._digraph = None
+		self._task_queues.fetch.clear()
+
+	def _choose_pkg(self):
+		"""
+		Choose a task that has all it's dependencies satisfied.
+		"""
+
+		if self._choose_pkg_return_early:
+			return None
+
+		if self._digraph is None:
+			if (self._jobs or self._task_queues.merge) and \
+				not ("--nodeps" in self.myopts and \
+				(self._max_jobs is True or self._max_jobs > 1)):
+				self._choose_pkg_return_early = True
+				return None
+			return self._pkg_queue.pop(0)
+
+		if not (self._jobs or self._task_queues.merge):
+			return self._pkg_queue.pop(0)
+
+		self._prune_digraph()
+
+		chosen_pkg = None
+		later = set(self._pkg_queue)
+		for pkg in self._pkg_queue:
+			later.remove(pkg)
+			if not self._dependent_on_scheduled_merges(pkg, later):
+				chosen_pkg = pkg
+				break
+
+		if chosen_pkg is not None:
+			self._pkg_queue.remove(chosen_pkg)
+
+		if chosen_pkg is None:
+			# There's no point in searching for a package to
+			# choose until at least one of the existing jobs
+			# completes.
+			self._choose_pkg_return_early = True
+
+		return chosen_pkg
+
+	def _dependent_on_scheduled_merges(self, pkg, later):
+		"""
+		Traverse the subgraph of the given packages deep dependencies
+		to see if it contains any scheduled merges.
+		@param pkg: a package to check dependencies for
+		@type pkg: Package
+		@param later: packages for which dependence should be ignored
+			since they will be merged later than pkg anyway and therefore
+			delaying the merge of pkg will not result in a more optimal
+			merge order
+		@type later: set
+		@rtype: bool
+		@returns: True if the package is dependent, False otherwise.
+		"""
+
+		graph = self._digraph
+		completed_tasks = self._completed_tasks
+
+		dependent = False
+		traversed_nodes = set([pkg])
+		direct_deps = graph.child_nodes(pkg)
+		node_stack = direct_deps
+		direct_deps = frozenset(direct_deps)
+		while node_stack:
+			node = node_stack.pop()
+			if node in traversed_nodes:
+				continue
+			traversed_nodes.add(node)
+			if not ((node.installed and node.operation == "nomerge") or \
+				(node.operation == "uninstall" and \
+				node not in direct_deps) or \
+				node in completed_tasks or \
+				node in later):
+				dependent = True
+				break
+			node_stack.extend(graph.child_nodes(node))
+
+		return dependent
+
+	def _allocate_config(self, root):
+		"""
+		Allocate a unique config instance for a task in order
+		to prevent interference between parallel tasks.
+		"""
+		if self._config_pool[root]:
+			temp_settings = self._config_pool[root].pop()
+		else:
+			temp_settings = portage.config(clone=self.pkgsettings[root])
+		# Since config.setcpv() isn't guaranteed to call config.reset() due to
+		# performance reasons, call it here to make sure all settings from the
+		# previous package get flushed out (such as PORTAGE_LOG_FILE).
+		temp_settings.reload()
+		temp_settings.reset()
+		return temp_settings
+
+	def _deallocate_config(self, settings):
+		self._config_pool[settings["ROOT"]].append(settings)
+
+	def _main_loop(self):
+
+		# Only allow 1 job max if a restart is scheduled
+		# due to portage update.
+		if self._is_restart_scheduled() or \
+			self._opts_no_background.intersection(self.myopts):
+			self._set_max_jobs(1)
+
+		merge_queue = self._task_queues.merge
+
+		while self._schedule():
+			if self._poll_event_handlers:
+				self._poll_loop()
+
+		while True:
+			self._schedule()
+			if not (self._jobs or merge_queue):
+				break
+			if self._poll_event_handlers:
+				self._poll_loop()
+
+	def _keep_scheduling(self):
+		return bool(self._pkg_queue and \
+			not (self._failed_pkgs and not self._build_opts.fetchonly))
+
+	def _schedule_tasks(self):
+
+		# When the number of jobs drops to zero, process all waiting merges.
+		if not self._jobs and self._merge_wait_queue:
+			for task in self._merge_wait_queue:
+				task.addExitListener(self._merge_wait_exit_handler)
+				self._task_queues.merge.add(task)
+			self._status_display.merges = len(self._task_queues.merge)
+			self._merge_wait_scheduled.extend(self._merge_wait_queue)
+			del self._merge_wait_queue[:]
+
+		self._schedule_tasks_imp()
+		self._status_display.display()
+
+		state_change = 0
+		for q in self._task_queues.values():
+			if q.schedule():
+				state_change += 1
+
+		# Cancel prefetchers if they're the only reason
+		# the main poll loop is still running.
+		if self._failed_pkgs and not self._build_opts.fetchonly and \
+			not (self._jobs or self._task_queues.merge) and \
+			self._task_queues.fetch:
+			self._task_queues.fetch.clear()
+			state_change += 1
+
+		if state_change:
+			self._schedule_tasks_imp()
+			self._status_display.display()
+
+		return self._keep_scheduling()
+
+	def _job_delay(self):
+		"""
+		@rtype: bool
+		@returns: True if job scheduling should be delayed, False otherwise.
+		"""
+
+		if self._jobs and self._max_load is not None:
+
+			current_time = time.time()
+
+			delay = self._job_delay_factor * self._jobs ** self._job_delay_exp
+			if delay > self._job_delay_max:
+				delay = self._job_delay_max
+			if (current_time - self._previous_job_start_time) < delay:
+				return True
+
+		return False
+
+	def _schedule_tasks_imp(self):
+		"""
+		@rtype: bool
+		@returns: True if state changed, False otherwise.
+		"""
+
+		state_change = 0
+
+		while True:
+
+			if not self._keep_scheduling():
+				return bool(state_change)
+
+			if self._choose_pkg_return_early or \
+				self._merge_wait_scheduled or \
+				(self._jobs and self._unsatisfied_system_deps) or \
+				not self._can_add_job() or \
+				self._job_delay():
+				return bool(state_change)
+
+			pkg = self._choose_pkg()
+			if pkg is None:
+				return bool(state_change)
+
+			state_change += 1
+
+			if not pkg.installed:
+				self._pkg_count.curval += 1
+
+			task = self._task(pkg)
+
+			if pkg.installed:
+				merge = PackageMerge(merge=task)
+				merge.addExitListener(self._merge_exit)
+				self._task_queues.merge.add(merge)
+
+			elif pkg.built:
+				self._jobs += 1
+				self._previous_job_start_time = time.time()
+				self._status_display.running = self._jobs
+				task.addExitListener(self._extract_exit)
+				self._task_queues.jobs.add(task)
+
+			else:
+				self._jobs += 1
+				self._previous_job_start_time = time.time()
+				self._status_display.running = self._jobs
+				task.addExitListener(self._build_exit)
+				self._task_queues.jobs.add(task)
+
+		return bool(state_change)
+
+	def _task(self, pkg):
+
+		pkg_to_replace = None
+		if pkg.operation != "uninstall":
+			vardb = pkg.root_config.trees["vartree"].dbapi
+			previous_cpv = vardb.match(pkg.slot_atom)
+			if previous_cpv:
+				previous_cpv = previous_cpv.pop()
+				pkg_to_replace = self._pkg(previous_cpv,
+					"installed", pkg.root_config, installed=True)
+
+		task = MergeListItem(args_set=self._args_set,
+			background=self._background, binpkg_opts=self._binpkg_opts,
+			build_opts=self._build_opts,
+			config_pool=self._ConfigPool(pkg.root,
+			self._allocate_config, self._deallocate_config),
+			emerge_opts=self.myopts,
+			find_blockers=self._find_blockers(pkg), logger=self._logger,
+			mtimedb=self._mtimedb, pkg=pkg, pkg_count=self._pkg_count.copy(),
+			pkg_to_replace=pkg_to_replace,
+			prefetcher=self._prefetchers.get(pkg),
+			scheduler=self._sched_iface,
+			settings=self._allocate_config(pkg.root),
+			statusMessage=self._status_msg,
+			world_atom=self._world_atom)
+
+		return task
+
+	def _failed_pkg_msg(self, failed_pkg, action, preposition):
+		pkg = failed_pkg.pkg
+		msg = "%s to %s %s" % \
+			(bad("Failed"), action, colorize("INFORM", pkg.cpv))
+		if pkg.root != "/":
+			msg += " %s %s" % (preposition, pkg.root)
+
+		log_path = self._locate_failure_log(failed_pkg)
+		if log_path is not None:
+			msg += ", Log file:"
+		self._status_msg(msg)
+
+		if log_path is not None:
+			self._status_msg(" '%s'" % (colorize("INFORM", log_path),))
+
+	def _status_msg(self, msg):
+		"""
+		Display a brief status message (no newlines) in the status display.
+		This is called by tasks to provide feedback to the user. This
+		delegates the resposibility of generating \r and \n control characters,
+		to guarantee that lines are created or erased when necessary and
+		appropriate.
+
+		@type msg: str
+		@param msg: a brief status message (no newlines allowed)
+		"""
+		if not self._background:
+			writemsg_level("\n")
+		self._status_display.displayMessage(msg)
+
+	def _save_resume_list(self):
+		"""
+		Do this before verifying the ebuild Manifests since it might
+		be possible for the user to use --resume --skipfirst get past
+		a non-essential package with a broken digest.
+		"""
+		mtimedb = self._mtimedb
+		mtimedb["resume"]["mergelist"] = [list(x) \
+			for x in self._mergelist \
+			if isinstance(x, Package) and x.operation == "merge"]
+
+		mtimedb.commit()
+
+	def _calc_resume_list(self):
+		"""
+		Use the current resume list to calculate a new one,
+		dropping any packages with unsatisfied deps.
+		@rtype: bool
+		@returns: True if successful, False otherwise.
+		"""
+		print colorize("GOOD", "*** Resuming merge...")
+
+		if self._show_list():
+			if "--tree" in self.myopts:
+				portage.writemsg_stdout("\n" + \
+					darkgreen("These are the packages that " + \
+					"would be merged, in reverse order:\n\n"))
+
+			else:
+				portage.writemsg_stdout("\n" + \
+					darkgreen("These are the packages that " + \
+					"would be merged, in order:\n\n"))
+
+		show_spinner = "--quiet" not in self.myopts and \
+			"--nodeps" not in self.myopts
+
+		if show_spinner:
+			print "Calculating dependencies  ",
+
+		myparams = create_depgraph_params(self.myopts, None)
+		success = False
+		e = None
+		try:
+			success, mydepgraph, dropped_tasks = resume_depgraph(
+				self.settings, self.trees, self._mtimedb, self.myopts,
+				myparams, self._spinner)
+		except depgraph.UnsatisfiedResumeDep, exc:
+			# rename variable to avoid python-3.0 error:
+			# SyntaxError: can not delete variable 'e' referenced in nested
+			#              scope
+			e = exc
+			mydepgraph = e.depgraph
+			dropped_tasks = set()
+
+		if show_spinner:
+			print "\b\b... done!"
+
+		if e is not None:
+			def unsatisfied_resume_dep_msg():
+				mydepgraph.display_problems()
+				out = portage.output.EOutput()
+				out.eerror("One or more packages are either masked or " + \
+					"have missing dependencies:")
+				out.eerror("")
+				indent = "  "
+				show_parents = set()
+				for dep in e.value:
+					if dep.parent in show_parents:
+						continue
+					show_parents.add(dep.parent)
+					if dep.atom is None:
+						out.eerror(indent + "Masked package:")
+						out.eerror(2 * indent + str(dep.parent))
+						out.eerror("")
+					else:
+						out.eerror(indent + str(dep.atom) + " pulled in by:")
+						out.eerror(2 * indent + str(dep.parent))
+						out.eerror("")
+				msg = "The resume list contains packages " + \
+					"that are either masked or have " + \
+					"unsatisfied dependencies. " + \
+					"Please restart/continue " + \
+					"the operation manually, or use --skipfirst " + \
+					"to skip the first package in the list and " + \
+					"any other packages that may be " + \
+					"masked or have missing dependencies."
+				for line in textwrap.wrap(msg, 72):
+					out.eerror(line)
+			self._post_mod_echo_msgs.append(unsatisfied_resume_dep_msg)
+			return False
+
+		if success and self._show_list():
+			mylist = mydepgraph.altlist()
+			if mylist:
+				if "--tree" in self.myopts:
+					mylist.reverse()
+				mydepgraph.display(mylist, favorites=self._favorites)
+
+		if not success:
+			self._post_mod_echo_msgs.append(mydepgraph.display_problems)
+			return False
+		mydepgraph.display_problems()
+
+		mylist = mydepgraph.altlist()
+		mydepgraph.break_refs(mylist)
+		mydepgraph.break_refs(dropped_tasks)
+		self._mergelist = mylist
+		self._set_digraph(mydepgraph.schedulerGraph())
+
+		msg_width = 75
+		for task in dropped_tasks:
+			if not (isinstance(task, Package) and task.operation == "merge"):
+				continue
+			pkg = task
+			msg = "emerge --keep-going:" + \
+				" %s" % (pkg.cpv,)
+			if pkg.root != "/":
+				msg += " for %s" % (pkg.root,)
+			msg += " dropped due to unsatisfied dependency."
+			for line in textwrap.wrap(msg, msg_width):
+				eerror(line, phase="other", key=pkg.cpv)
+			settings = self.pkgsettings[pkg.root]
+			# Ensure that log collection from $T is disabled inside
+			# elog_process(), since any logs that might exist are
+			# not valid here.
+			settings.pop("T", None)
+			portage.elog.elog_process(pkg.cpv, settings)
+			self._failed_pkgs_all.append(self._failed_pkg(pkg=pkg))
+
+		return True
+
+	def _show_list(self):
+		myopts = self.myopts
+		if "--quiet" not in myopts and \
+			("--ask" in myopts or "--tree" in myopts or \
+			"--verbose" in myopts):
+			return True
+		return False
+
+	def _world_atom(self, pkg):
+		"""
+		Add the package to the world file, but only if
+		it's supposed to be added. Otherwise, do nothing.
+		"""
+
+		if set(("--buildpkgonly", "--fetchonly",
+			"--fetch-all-uri",
+			"--oneshot", "--onlydeps",
+			"--pretend")).intersection(self.myopts):
+			return
+
+		if pkg.root != self.target_root:
+			return
+
+		args_set = self._args_set
+		if not args_set.findAtomForPackage(pkg):
+			return
+
+		logger = self._logger
+		pkg_count = self._pkg_count
+		root_config = pkg.root_config
+		world_set = root_config.sets["world"]
+		world_locked = False
+		if hasattr(world_set, "lock"):
+			world_set.lock()
+			world_locked = True
+
+		try:
+			if hasattr(world_set, "load"):
+				world_set.load() # maybe it's changed on disk
+
+			atom = create_world_atom(pkg, args_set, root_config)
+			if atom:
+				if hasattr(world_set, "add"):
+					self._status_msg(('Recording %s in "world" ' + \
+						'favorites file...') % atom)
+					logger.log(" === (%s of %s) Updating world file (%s)" % \
+						(pkg_count.curval, pkg_count.maxval, pkg.cpv))
+					world_set.add(atom)
+				else:
+					writemsg_level('\n!!! Unable to record %s in "world"\n' % \
+						(atom,), level=logging.WARN, noiselevel=-1)
+		finally:
+			if world_locked:
+				world_set.unlock()
+
+	def _pkg(self, cpv, type_name, root_config, installed=False):
+		"""
+		Get a package instance from the cache, or create a new
+		one if necessary. Raises KeyError from aux_get if it
+		failures for some reason (package does not exist or is
+		corrupt).
+		"""
+		operation = "merge"
+		if installed:
+			operation = "nomerge"
+
+		if self._digraph is not None:
+			# Reuse existing instance when available.
+			pkg = self._digraph.get(
+				(type_name, root_config.root, cpv, operation))
+			if pkg is not None:
+				return pkg
+
+		tree_type = depgraph.pkg_tree_map[type_name]
+		db = root_config.trees[tree_type].dbapi
+		db_keys = list(self.trees[root_config.root][
+			tree_type].dbapi._aux_cache_keys)
+		metadata = izip(db_keys, db.aux_get(cpv, db_keys))
+		pkg = Package(cpv=cpv, metadata=metadata,
+			root_config=root_config, installed=installed)
+		if type_name == "ebuild":
+			settings = self.pkgsettings[root_config.root]
+			settings.setcpv(pkg)
+			pkg.metadata["USE"] = settings["PORTAGE_USE"]
+			pkg.metadata['CHOST'] = settings.get('CHOST', '')
+
+		return pkg
diff --git a/pym/_emerge/__init__.py b/pym/_emerge/__init__.py
index f0b994a4c..47c20a2f3 100644
--- a/pym/_emerge/__init__.py
+++ b/pym/_emerge/__init__.py
@@ -9,8 +9,6 @@ import shlex
 import signal
 import sys
 import textwrap
-import weakref
-import gc
 import os, stat
 import platform
 
@@ -23,13 +21,11 @@ except ImportError:
 
 from portage import digraph
 from portage.const import NEWS_LIB_PATH
-from portage.cache.mappings import slot_dict_class
 
 import _emerge.help
 import portage.xpak, commands, errno, re, socket, time
-from portage.output import blue, bold, colorize, darkblue, darkgreen, green, \
-	nc_len, red, teal, turquoise, \
-	xtermTitleReset, yellow
+from portage.output import blue, bold, colorize, darkgreen, \
+	red, xtermTitleReset, yellow
 from portage.output import create_color_func
 good = create_color_func("GOOD")
 bad = create_color_func("BAD")
@@ -42,7 +38,6 @@ import portage.locks
 import portage.exception
 from portage.cache.cache_errors import CacheError
 from portage.data import secpass
-from portage.elog.messages import eerror
 from portage.util import normalize_path as normpath
 from portage.util import cmp_sort_key, writemsg, writemsg_level
 from portage.sets import load_default_config, SETPREFIX
@@ -50,46 +45,29 @@ from portage.sets.base import InternalPackageSet
 
 from itertools import chain, izip
 
-from _emerge.SlotObject import SlotObject
-from _emerge.DepPriority import DepPriority
-from _emerge.BlockerDepPriority import BlockerDepPriority
-from _emerge.UnmergeDepPriority import UnmergeDepPriority
-from _emerge.DepPriorityNormalRange import DepPriorityNormalRange
+from _emerge.clear_caches import clear_caches
+from _emerge.countdown import countdown
+from _emerge.create_depgraph_params import create_depgraph_params
+from _emerge.Dependency import Dependency
+from _emerge.depgraph import depgraph, resume_depgraph
 from _emerge.DepPrioritySatisfiedRange import DepPrioritySatisfiedRange
+from _emerge.emergelog import emergelog
+from _emerge._flush_elog_mod_echo import _flush_elog_mod_echo
+from _emerge.is_valid_package_atom import is_valid_package_atom
+from _emerge.MetadataRegen import MetadataRegen
 from _emerge.Package import Package
-from _emerge.Blocker import Blocker
-from _emerge.BlockerDB import BlockerDB
-from _emerge.EbuildFetcher import EbuildFetcher
-from _emerge.EbuildPhase import EbuildPhase
-from _emerge.BinpkgPrefetcher import BinpkgPrefetcher
-from _emerge.PackageMerge import PackageMerge
-from _emerge.DependencyArg import DependencyArg
-from _emerge.AtomArg import AtomArg
-from _emerge.PackageArg import PackageArg
-from _emerge.SetArg import SetArg
-from _emerge.Dependency import Dependency
-from _emerge.BlockerCache import BlockerCache
-from _emerge.PackageVirtualDbapi import PackageVirtualDbapi
-from _emerge.RepoDisplay import RepoDisplay
-from _emerge.UseFlagDisplay import UseFlagDisplay
-from _emerge.SequentialTaskQueue import SequentialTaskQueue
 from _emerge.ProgressHandler import ProgressHandler
-from _emerge.stdout_spinner import stdout_spinner
-from _emerge.JobStatusDisplay import JobStatusDisplay
-from _emerge.PollScheduler import PollScheduler
-from _emerge.search import search
-from _emerge.visible import visible
-from _emerge.emergelog import emergelog, _emerge_log_dir
-from _emerge.userquery import userquery
-from _emerge.countdown import countdown
-from _emerge.unmerge import unmerge
-from _emerge.MergeListItem import MergeListItem
-from _emerge.MetadataRegen import MetadataRegen
 from _emerge.RootConfig import RootConfig
-from _emerge.format_size import format_size
-from _emerge.PackageCounters import PackageCounters
-from _emerge.FakeVartree import FakeVartree
+from _emerge.Scheduler import Scheduler
+from _emerge.search import search
+from _emerge.SetArg import SetArg
 from _emerge.show_invalid_depstring_notice import show_invalid_depstring_notice
+from _emerge.stdout_spinner import stdout_spinner
+from _emerge.unmerge import unmerge
+from _emerge.UnmergeDepPriority import UnmergeDepPriority
+from _emerge.UseFlagDisplay import UseFlagDisplay
+from _emerge.userquery import userquery
+
 
 actions = frozenset([
 "clean", "config", "depclean",
@@ -208,6547 +186,6 @@ def getportageversion(portdir, target_root, profile, chost, vardb):
 
 	return "Portage " + portage.VERSION +" ("+profilever+", "+gccver+", "+libcver+", "+unameout+")"
 
-def create_depgraph_params(myopts, myaction):
-	#configure emerge engine parameters
-	#
-	# self:      include _this_ package regardless of if it is merged.
-	# selective: exclude the package if it is merged
-	# recurse:   go into the dependencies
-	# deep:      go into the dependencies of already merged packages
-	# empty:     pretend nothing is merged
-	# complete:  completely account for all known dependencies
-	# remove:    build graph for use in removing packages
-	myparams = set(["recurse"])
-
-	if myaction == "remove":
-		myparams.add("remove")
-		myparams.add("complete")
-		return myparams
-
-	if "--update" in myopts or \
-		"--newuse" in myopts or \
-		"--reinstall" in myopts or \
-		"--noreplace" in myopts:
-		myparams.add("selective")
-	if "--emptytree" in myopts:
-		myparams.add("empty")
-		myparams.discard("selective")
-	if "--nodeps" in myopts:
-		myparams.discard("recurse")
-	if "--deep" in myopts:
-		myparams.add("deep")
-	if "--complete-graph" in myopts:
-		myparams.add("complete")
-	return myparams
-
-def create_world_atom(pkg, args_set, root_config):
-	"""Create a new atom for the world file if one does not exist.  If the
-	argument atom is precise enough to identify a specific slot then a slot
-	atom will be returned. Atoms that are in the system set may also be stored
-	in world since system atoms can only match one slot while world atoms can
-	be greedy with respect to slots.  Unslotted system packages will not be
-	stored in world."""
-
-	arg_atom = args_set.findAtomForPackage(pkg)
-	if not arg_atom:
-		return None
-	cp = portage.dep_getkey(arg_atom)
-	new_world_atom = cp
-	sets = root_config.sets
-	portdb = root_config.trees["porttree"].dbapi
-	vardb = root_config.trees["vartree"].dbapi
-	available_slots = set(portdb.aux_get(cpv, ["SLOT"])[0] \
-		for cpv in portdb.match(cp))
-	slotted = len(available_slots) > 1 or \
-		(len(available_slots) == 1 and "0" not in available_slots)
-	if not slotted:
-		# check the vdb in case this is multislot
-		available_slots = set(vardb.aux_get(cpv, ["SLOT"])[0] \
-			for cpv in vardb.match(cp))
-		slotted = len(available_slots) > 1 or \
-			(len(available_slots) == 1 and "0" not in available_slots)
-	if slotted and arg_atom != cp:
-		# If the user gave a specific atom, store it as a
-		# slot atom in the world file.
-		slot_atom = pkg.slot_atom
-
-		# For USE=multislot, there are a couple of cases to
-		# handle here:
-		#
-		# 1) SLOT="0", but the real SLOT spontaneously changed to some
-		#    unknown value, so just record an unslotted atom.
-		#
-		# 2) SLOT comes from an installed package and there is no
-		#    matching SLOT in the portage tree.
-		#
-		# Make sure that the slot atom is available in either the
-		# portdb or the vardb, since otherwise the user certainly
-		# doesn't want the SLOT atom recorded in the world file
-		# (case 1 above).  If it's only available in the vardb,
-		# the user may be trying to prevent a USE=multislot
-		# package from being removed by --depclean (case 2 above).
-
-		mydb = portdb
-		if not portdb.match(slot_atom):
-			# SLOT seems to come from an installed multislot package
-			mydb = vardb
-		# If there is no installed package matching the SLOT atom,
-		# it probably changed SLOT spontaneously due to USE=multislot,
-		# so just record an unslotted atom.
-		if vardb.match(slot_atom):
-			# Now verify that the argument is precise
-			# enough to identify a specific slot.
-			matches = mydb.match(arg_atom)
-			matched_slots = set()
-			for cpv in matches:
-				matched_slots.add(mydb.aux_get(cpv, ["SLOT"])[0])
-			if len(matched_slots) == 1:
-				new_world_atom = slot_atom
-
-	if new_world_atom == sets["world"].findAtomForPackage(pkg):
-		# Both atoms would be identical, so there's nothing to add.
-		return None
-	if not slotted:
-		# Unlike world atoms, system atoms are not greedy for slots, so they
-		# can't be safely excluded from world if they are slotted.
-		system_atom = sets["system"].findAtomForPackage(pkg)
-		if system_atom:
-			if not portage.dep_getkey(system_atom).startswith("virtual/"):
-				return None
-			# System virtuals aren't safe to exclude from world since they can
-			# match multiple old-style virtuals but only one of them will be
-			# pulled in by update or depclean.
-			providers = portdb.mysettings.getvirtuals().get(
-				portage.dep_getkey(system_atom))
-			if providers and len(providers) == 1 and providers[0] == cp:
-				return None
-	return new_world_atom
-
-def filter_iuse_defaults(iuse):
-	for flag in iuse:
-		if flag.startswith("+") or flag.startswith("-"):
-			yield flag[1:]
-		else:
-			yield flag
-
-def _find_deep_system_runtime_deps(graph):
-	deep_system_deps = set()
-	node_stack = []
-	for node in graph:
-		if not isinstance(node, Package) or \
-			node.operation == 'uninstall':
-			continue
-		if node.root_config.sets['system'].findAtomForPackage(node):
-			node_stack.append(node)
-
-	def ignore_priority(priority):
-		"""
-		Ignore non-runtime priorities.
-		"""
-		if isinstance(priority, DepPriority) and \
-			(priority.runtime or priority.runtime_post):
-			return False
-		return True
-
-	while node_stack:
-		node = node_stack.pop()
-		if node in deep_system_deps:
-			continue
-		deep_system_deps.add(node)
-		for child in graph.child_nodes(node, ignore_priority=ignore_priority):
-			if not isinstance(child, Package) or \
-				child.operation == 'uninstall':
-				continue
-			node_stack.append(child)
-
-	return deep_system_deps
-
-def get_masking_status(pkg, pkgsettings, root_config):
-
-	mreasons = portage.getmaskingstatus(
-		pkg, settings=pkgsettings,
-		portdb=root_config.trees["porttree"].dbapi)
-
-	if not pkg.installed:
-		if not pkgsettings._accept_chost(pkg.cpv, pkg.metadata):
-			mreasons.append("CHOST: %s" % \
-				pkg.metadata["CHOST"])
-
-	if not pkg.metadata["SLOT"]:
-		mreasons.append("invalid: SLOT is undefined")
-
-	return mreasons
-
-def get_mask_info(root_config, cpv, pkgsettings,
-	db, pkg_type, built, installed, db_keys):
-	eapi_masked = False
-	try:
-		metadata = dict(izip(db_keys,
-			db.aux_get(cpv, db_keys)))
-	except KeyError:
-		metadata = None
-	if metadata and not built:
-		pkgsettings.setcpv(cpv, mydb=metadata)
-		metadata["USE"] = pkgsettings["PORTAGE_USE"]
-		metadata['CHOST'] = pkgsettings.get('CHOST', '')
-	if metadata is None:
-		mreasons = ["corruption"]
-	else:
-		eapi = metadata['EAPI']
-		if eapi[:1] == '-':
-			eapi = eapi[1:]
-		if not portage.eapi_is_supported(eapi):
-			mreasons = ['EAPI %s' % eapi]
-		else:
-			pkg = Package(type_name=pkg_type, root_config=root_config,
-				cpv=cpv, built=built, installed=installed, metadata=metadata)
-			mreasons = get_masking_status(pkg, pkgsettings, root_config)
-	return metadata, mreasons
-
-def show_masked_packages(masked_packages):
-	shown_licenses = set()
-	shown_comments = set()
-	# Maybe there is both an ebuild and a binary. Only
-	# show one of them to avoid redundant appearance.
-	shown_cpvs = set()
-	have_eapi_mask = False
-	for (root_config, pkgsettings, cpv,
-		metadata, mreasons) in masked_packages:
-		if cpv in shown_cpvs:
-			continue
-		shown_cpvs.add(cpv)
-		comment, filename = None, None
-		if "package.mask" in mreasons:
-			comment, filename = \
-				portage.getmaskingreason(
-				cpv, metadata=metadata,
-				settings=pkgsettings,
-				portdb=root_config.trees["porttree"].dbapi,
-				return_location=True)
-		missing_licenses = []
-		if metadata:
-			if not portage.eapi_is_supported(metadata["EAPI"]):
-				have_eapi_mask = True
-			try:
-				missing_licenses = \
-					pkgsettings._getMissingLicenses(
-						cpv, metadata)
-			except portage.exception.InvalidDependString:
-				# This will have already been reported
-				# above via mreasons.
-				pass
-
-		print "- "+cpv+" (masked by: "+", ".join(mreasons)+")"
-		if comment and comment not in shown_comments:
-			print filename+":"
-			print comment
-			shown_comments.add(comment)
-		portdb = root_config.trees["porttree"].dbapi
-		for l in missing_licenses:
-			l_path = portdb.findLicensePath(l)
-			if l in shown_licenses:
-				continue
-			msg = ("A copy of the '%s' license" + \
-			" is located at '%s'.") % (l, l_path)
-			print msg
-			print
-			shown_licenses.add(l)
-	return have_eapi_mask
-
-class depgraph(object):
-
-	pkg_tree_map = RootConfig.pkg_tree_map
-
-	_dep_keys = ["DEPEND", "RDEPEND", "PDEPEND"]
-
-	def __init__(self, settings, trees, myopts, myparams, spinner):
-		self.settings = settings
-		self.target_root = settings["ROOT"]
-		self.myopts = myopts
-		self.myparams = myparams
-		self.edebug = 0
-		if settings.get("PORTAGE_DEBUG", "") == "1":
-			self.edebug = 1
-		self.spinner = spinner
-		self._running_root = trees["/"]["root_config"]
-		self._opts_no_restart = Scheduler._opts_no_restart
-		self.pkgsettings = {}
-		# Maps slot atom to package for each Package added to the graph.
-		self._slot_pkg_map = {}
-		# Maps nodes to the reasons they were selected for reinstallation.
-		self._reinstall_nodes = {}
-		self.mydbapi = {}
-		self.trees = {}
-		self._trees_orig = trees
-		self.roots = {}
-		# Contains a filtered view of preferred packages that are selected
-		# from available repositories.
-		self._filtered_trees = {}
-		# Contains installed packages and new packages that have been added
-		# to the graph.
-		self._graph_trees = {}
-		# All Package instances
-		self._pkg_cache = {}
-		for myroot in trees:
-			self.trees[myroot] = {}
-			# Create a RootConfig instance that references
-			# the FakeVartree instead of the real one.
-			self.roots[myroot] = RootConfig(
-				trees[myroot]["vartree"].settings,
-				self.trees[myroot],
-				trees[myroot]["root_config"].setconfig)
-			for tree in ("porttree", "bintree"):
-				self.trees[myroot][tree] = trees[myroot][tree]
-			self.trees[myroot]["vartree"] = \
-				FakeVartree(trees[myroot]["root_config"],
-					pkg_cache=self._pkg_cache)
-			self.pkgsettings[myroot] = portage.config(
-				clone=self.trees[myroot]["vartree"].settings)
-			self._slot_pkg_map[myroot] = {}
-			vardb = self.trees[myroot]["vartree"].dbapi
-			preload_installed_pkgs = "--nodeps" not in self.myopts and \
-				"--buildpkgonly" not in self.myopts
-			# This fakedbapi instance will model the state that the vdb will
-			# have after new packages have been installed.
-			fakedb = PackageVirtualDbapi(vardb.settings)
-			if preload_installed_pkgs:
-				for pkg in vardb:
-					self.spinner.update()
-					# This triggers metadata updates via FakeVartree.
-					vardb.aux_get(pkg.cpv, [])
-					fakedb.cpv_inject(pkg)
-
-			# Now that the vardb state is cached in our FakeVartree,
-			# we won't be needing the real vartree cache for awhile.
-			# To make some room on the heap, clear the vardbapi
-			# caches.
-			trees[myroot]["vartree"].dbapi._clear_cache()
-			gc.collect()
-
-			self.mydbapi[myroot] = fakedb
-			def graph_tree():
-				pass
-			graph_tree.dbapi = fakedb
-			self._graph_trees[myroot] = {}
-			self._filtered_trees[myroot] = {}
-			# Substitute the graph tree for the vartree in dep_check() since we
-			# want atom selections to be consistent with package selections
-			# have already been made.
-			self._graph_trees[myroot]["porttree"]   = graph_tree
-			self._graph_trees[myroot]["vartree"]    = graph_tree
-			def filtered_tree():
-				pass
-			filtered_tree.dbapi = self._dep_check_composite_db(self, myroot)
-			self._filtered_trees[myroot]["porttree"] = filtered_tree
-
-			# Passing in graph_tree as the vartree here could lead to better
-			# atom selections in some cases by causing atoms for packages that
-			# have been added to the graph to be preferred over other choices.
-			# However, it can trigger atom selections that result in
-			# unresolvable direct circular dependencies. For example, this
-			# happens with gwydion-dylan which depends on either itself or
-			# gwydion-dylan-bin. In case gwydion-dylan is not yet installed,
-			# gwydion-dylan-bin needs to be selected in order to avoid a
-			# an unresolvable direct circular dependency.
-			#
-			# To solve the problem described above, pass in "graph_db" so that
-			# packages that have been added to the graph are distinguishable
-			# from other available packages and installed packages. Also, pass
-			# the parent package into self._select_atoms() calls so that
-			# unresolvable direct circular dependencies can be detected and
-			# avoided when possible.
-			self._filtered_trees[myroot]["graph_db"] = graph_tree.dbapi
-			self._filtered_trees[myroot]["vartree"] = self.trees[myroot]["vartree"]
-
-			dbs = []
-			portdb = self.trees[myroot]["porttree"].dbapi
-			bindb  = self.trees[myroot]["bintree"].dbapi
-			vardb  = self.trees[myroot]["vartree"].dbapi
-			#               (db, pkg_type, built, installed, db_keys)
-			if "--usepkgonly" not in self.myopts:
-				db_keys = list(portdb._aux_cache_keys)
-				dbs.append((portdb, "ebuild", False, False, db_keys))
-			if "--usepkg" in self.myopts:
-				db_keys = list(bindb._aux_cache_keys)
-				dbs.append((bindb,  "binary", True, False, db_keys))
-			db_keys = list(trees[myroot]["vartree"].dbapi._aux_cache_keys)
-			dbs.append((vardb, "installed", True, True, db_keys))
-			self._filtered_trees[myroot]["dbs"] = dbs
-			if "--usepkg" in self.myopts:
-				self.trees[myroot]["bintree"].populate(
-					"--getbinpkg" in self.myopts,
-					"--getbinpkgonly" in self.myopts)
-		del trees
-
-		self.digraph=portage.digraph()
-		# contains all sets added to the graph
-		self._sets = {}
-		# contains atoms given as arguments
-		self._sets["args"] = InternalPackageSet()
-		# contains all atoms from all sets added to the graph, including
-		# atoms given as arguments
-		self._set_atoms = InternalPackageSet()
-		self._atom_arg_map = {}
-		# contains all nodes pulled in by self._set_atoms
-		self._set_nodes = set()
-		# Contains only Blocker -> Uninstall edges
-		self._blocker_uninstalls = digraph()
-		# Contains only Package -> Blocker edges
-		self._blocker_parents = digraph()
-		# Contains only irrelevant Package -> Blocker edges
-		self._irrelevant_blockers = digraph()
-		# Contains only unsolvable Package -> Blocker edges
-		self._unsolvable_blockers = digraph()
-		# Contains all Blocker -> Blocked Package edges
-		self._blocked_pkgs = digraph()
-		# Contains world packages that have been protected from
-		# uninstallation but may not have been added to the graph
-		# if the graph is not complete yet.
-		self._blocked_world_pkgs = {}
-		self._slot_collision_info = {}
-		# Slot collision nodes are not allowed to block other packages since
-		# blocker validation is only able to account for one package per slot.
-		self._slot_collision_nodes = set()
-		self._parent_atoms = {}
-		self._slot_conflict_parent_atoms = set()
-		self._serialized_tasks_cache = None
-		self._scheduler_graph = None
-		self._displayed_list = None
-		self._pprovided_args = []
-		self._missing_args = []
-		self._masked_installed = set()
-		self._unsatisfied_deps_for_display = []
-		self._unsatisfied_blockers_for_display = None
-		self._circular_deps_for_display = None
-		self._dep_stack = []
-		self._dep_disjunctive_stack = []
-		self._unsatisfied_deps = []
-		self._initially_unsatisfied_deps = []
-		self._ignored_deps = []
-		self._required_set_names = set(["system", "world"])
-		self._select_atoms = self._select_atoms_highest_available
-		self._select_package = self._select_pkg_highest_available
-		self._highest_pkg_cache = {}
-
-	def _show_slot_collision_notice(self):
-		"""Show an informational message advising the user to mask one of the
-		the packages. In some cases it may be possible to resolve this
-		automatically, but support for backtracking (removal nodes that have
-		already been selected) will be required in order to handle all possible
-		cases.
-		"""
-
-		if not self._slot_collision_info:
-			return
-
-		self._show_merge_list()
-
-		msg = []
-		msg.append("\n!!! Multiple package instances within a single " + \
-			"package slot have been pulled\n")
-		msg.append("!!! into the dependency graph, resulting" + \
-			" in a slot conflict:\n\n")
-		indent = "  "
-		# Max number of parents shown, to avoid flooding the display.
-		max_parents = 3
-		explanation_columns = 70
-		explanations = 0
-		for (slot_atom, root), slot_nodes \
-			in self._slot_collision_info.iteritems():
-			msg.append(str(slot_atom))
-			msg.append("\n\n")
-
-			for node in slot_nodes:
-				msg.append(indent)
-				msg.append(str(node))
-				parent_atoms = self._parent_atoms.get(node)
-				if parent_atoms:
-					pruned_list = set()
-					# Prefer conflict atoms over others.
-					for parent_atom in parent_atoms:
-						if len(pruned_list) >= max_parents:
-							break
-						if parent_atom in self._slot_conflict_parent_atoms:
-							pruned_list.add(parent_atom)
-
-					# If this package was pulled in by conflict atoms then
-					# show those alone since those are the most interesting.
-					if not pruned_list:
-						# When generating the pruned list, prefer instances
-						# of DependencyArg over instances of Package.
-						for parent_atom in parent_atoms:
-							if len(pruned_list) >= max_parents:
-								break
-							parent, atom = parent_atom
-							if isinstance(parent, DependencyArg):
-								pruned_list.add(parent_atom)
-						# Prefer Packages instances that themselves have been
-						# pulled into collision slots.
-						for parent_atom in parent_atoms:
-							if len(pruned_list) >= max_parents:
-								break
-							parent, atom = parent_atom
-							if isinstance(parent, Package) and \
-								(parent.slot_atom, parent.root) \
-								in self._slot_collision_info:
-								pruned_list.add(parent_atom)
-						for parent_atom in parent_atoms:
-							if len(pruned_list) >= max_parents:
-								break
-							pruned_list.add(parent_atom)
-					omitted_parents = len(parent_atoms) - len(pruned_list)
-					parent_atoms = pruned_list
-					msg.append(" pulled in by\n")
-					for parent_atom in parent_atoms:
-						parent, atom = parent_atom
-						msg.append(2*indent)
-						if isinstance(parent,
-							(PackageArg, AtomArg)):
-							# For PackageArg and AtomArg types, it's
-							# redundant to display the atom attribute.
-							msg.append(str(parent))
-						else:
-							# Display the specific atom from SetArg or
-							# Package types.
-							msg.append("%s required by %s" % (atom, parent))
-						msg.append("\n")
-					if omitted_parents:
-						msg.append(2*indent)
-						msg.append("(and %d more)\n" % omitted_parents)
-				else:
-					msg.append(" (no parents)\n")
-				msg.append("\n")
-			explanation = self._slot_conflict_explanation(slot_nodes)
-			if explanation:
-				explanations += 1
-				msg.append(indent + "Explanation:\n\n")
-				for line in textwrap.wrap(explanation, explanation_columns):
-					msg.append(2*indent + line + "\n")
-				msg.append("\n")
-		msg.append("\n")
-		sys.stderr.write("".join(msg))
-		sys.stderr.flush()
-
-		explanations_for_all = explanations == len(self._slot_collision_info)
-
-		if explanations_for_all or "--quiet" in self.myopts:
-			return
-
-		msg = []
-		msg.append("It may be possible to solve this problem ")
-		msg.append("by using package.mask to prevent one of ")
-		msg.append("those packages from being selected. ")
-		msg.append("However, it is also possible that conflicting ")
-		msg.append("dependencies exist such that they are impossible to ")
-		msg.append("satisfy simultaneously.  If such a conflict exists in ")
-		msg.append("the dependencies of two different packages, then those ")
-		msg.append("packages can not be installed simultaneously.")
-
-		from formatter import AbstractFormatter, DumbWriter
-		f = AbstractFormatter(DumbWriter(sys.stderr, maxcol=72))
-		for x in msg:
-			f.add_flowing_data(x)
-		f.end_paragraph(1)
-
-		msg = []
-		msg.append("For more information, see MASKED PACKAGES ")
-		msg.append("section in the emerge man page or refer ")
-		msg.append("to the Gentoo Handbook.")
-		for x in msg:
-			f.add_flowing_data(x)
-		f.end_paragraph(1)
-		f.writer.flush()
-
-	def _slot_conflict_explanation(self, slot_nodes):
-		"""
-		When a slot conflict occurs due to USE deps, there are a few
-		different cases to consider:
-
-		1) New USE are correctly set but --newuse wasn't requested so an
-		   installed package with incorrect USE happened to get pulled
-		   into graph before the new one.
-
-		2) New USE are incorrectly set but an installed package has correct
-		   USE so it got pulled into the graph, and a new instance also got
-		   pulled in due to --newuse or an upgrade.
-
-		3) Multiple USE deps exist that can't be satisfied simultaneously,
-		   and multiple package instances got pulled into the same slot to
-		   satisfy the conflicting deps.
-
-		Currently, explanations and suggested courses of action are generated
-		for cases 1 and 2. Case 3 is too complex to give a useful suggestion.
-		"""
-
-		if len(slot_nodes) != 2:
-			# Suggestions are only implemented for
-			# conflicts between two packages.
-			return None
-
-		all_conflict_atoms = self._slot_conflict_parent_atoms
-		matched_node = None
-		matched_atoms = None
-		unmatched_node = None
-		for node in slot_nodes:
-			parent_atoms = self._parent_atoms.get(node)
-			if not parent_atoms:
-				# Normally, there are always parent atoms. If there are
-				# none then something unexpected is happening and there's
-				# currently no suggestion for this case.
-				return None
-			conflict_atoms = all_conflict_atoms.intersection(parent_atoms)
-			for parent_atom in conflict_atoms:
-				parent, atom = parent_atom
-				if not atom.use:
-					# Suggestions are currently only implemented for cases
-					# in which all conflict atoms have USE deps.
-					return None
-			if conflict_atoms:
-				if matched_node is not None:
-					# If conflict atoms match multiple nodes
-					# then there's no suggestion.
-					return None
-				matched_node = node
-				matched_atoms = conflict_atoms
-			else:
-				if unmatched_node is not None:
-					# Neither node is matched by conflict atoms, and
-					# there is no suggestion for this case.
-					return None
-				unmatched_node = node
-
-		if matched_node is None or unmatched_node is None:
-			# This shouldn't happen.
-			return None
-
-		if unmatched_node.installed and not matched_node.installed and \
-			unmatched_node.cpv == matched_node.cpv:
-			# If the conflicting packages are the same version then
-			# --newuse should be all that's needed. If they are different
-			# versions then there's some other problem.
-			return "New USE are correctly set, but --newuse wasn't" + \
-				" requested, so an installed package with incorrect USE " + \
-				"happened to get pulled into the dependency graph. " + \
-				"In order to solve " + \
-				"this, either specify the --newuse option or explicitly " + \
-				" reinstall '%s'." % matched_node.slot_atom
-
-		if matched_node.installed and not unmatched_node.installed:
-			atoms = sorted(set(atom for parent, atom in matched_atoms))
-			explanation = ("New USE for '%s' are incorrectly set. " + \
-				"In order to solve this, adjust USE to satisfy '%s'") % \
-				(matched_node.slot_atom, atoms[0])
-			if len(atoms) > 1:
-				for atom in atoms[1:-1]:
-					explanation += ", '%s'" % (atom,)
-				if len(atoms) > 2:
-					explanation += ","
-				explanation += " and '%s'" % (atoms[-1],)
-			explanation += "."
-			return explanation
-
-		return None
-
-	def _process_slot_conflicts(self):
-		"""
-		Process slot conflict data to identify specific atoms which
-		lead to conflict. These atoms only match a subset of the
-		packages that have been pulled into a given slot.
-		"""
-		for (slot_atom, root), slot_nodes \
-			in self._slot_collision_info.iteritems():
-
-			all_parent_atoms = set()
-			for pkg in slot_nodes:
-				parent_atoms = self._parent_atoms.get(pkg)
-				if not parent_atoms:
-					continue
-				all_parent_atoms.update(parent_atoms)
-
-			for pkg in slot_nodes:
-				parent_atoms = self._parent_atoms.get(pkg)
-				if parent_atoms is None:
-					parent_atoms = set()
-					self._parent_atoms[pkg] = parent_atoms
-				for parent_atom in all_parent_atoms:
-					if parent_atom in parent_atoms:
-						continue
-					# Use package set for matching since it will match via
-					# PROVIDE when necessary, while match_from_list does not.
-					parent, atom = parent_atom
-					atom_set = InternalPackageSet(
-						initial_atoms=(atom,))
-					if atom_set.findAtomForPackage(pkg):
-						parent_atoms.add(parent_atom)
-					else:
-						self._slot_conflict_parent_atoms.add(parent_atom)
-
-	def _reinstall_for_flags(self, forced_flags,
-		orig_use, orig_iuse, cur_use, cur_iuse):
-		"""Return a set of flags that trigger reinstallation, or None if there
-		are no such flags."""
-		if "--newuse" in self.myopts:
-			flags = set(orig_iuse.symmetric_difference(
-				cur_iuse).difference(forced_flags))
-			flags.update(orig_iuse.intersection(orig_use).symmetric_difference(
-				cur_iuse.intersection(cur_use)))
-			if flags:
-				return flags
-		elif "changed-use" == self.myopts.get("--reinstall"):
-			flags = orig_iuse.intersection(orig_use).symmetric_difference(
-				cur_iuse.intersection(cur_use))
-			if flags:
-				return flags
-		return None
-
-	def _create_graph(self, allow_unsatisfied=False):
-		dep_stack = self._dep_stack
-		dep_disjunctive_stack = self._dep_disjunctive_stack
-		while dep_stack or dep_disjunctive_stack:
-			self.spinner.update()
-			while dep_stack:
-				dep = dep_stack.pop()
-				if isinstance(dep, Package):
-					if not self._add_pkg_deps(dep,
-						allow_unsatisfied=allow_unsatisfied):
-						return 0
-					continue
-				if not self._add_dep(dep, allow_unsatisfied=allow_unsatisfied):
-					return 0
-			if dep_disjunctive_stack:
-				if not self._pop_disjunction(allow_unsatisfied):
-					return 0
-		return 1
-
-	def _add_dep(self, dep, allow_unsatisfied=False):
-		debug = "--debug" in self.myopts
-		buildpkgonly = "--buildpkgonly" in self.myopts
-		nodeps = "--nodeps" in self.myopts
-		empty = "empty" in self.myparams
-		deep = "deep" in self.myparams
-		update = "--update" in self.myopts and dep.depth <= 1
-		if dep.blocker:
-			if not buildpkgonly and \
-				not nodeps and \
-				dep.parent not in self._slot_collision_nodes:
-				if dep.parent.onlydeps:
-					# It's safe to ignore blockers if the
-					# parent is an --onlydeps node.
-					return 1
-				# The blocker applies to the root where
-				# the parent is or will be installed.
-				blocker = Blocker(atom=dep.atom,
-					eapi=dep.parent.metadata["EAPI"],
-					root=dep.parent.root)
-				self._blocker_parents.add(blocker, dep.parent)
-			return 1
-		dep_pkg, existing_node = self._select_package(dep.root, dep.atom,
-			onlydeps=dep.onlydeps)
-		if not dep_pkg:
-			if dep.priority.optional:
-				# This could be an unecessary build-time dep
-				# pulled in by --with-bdeps=y.
-				return 1
-			if allow_unsatisfied:
-				self._unsatisfied_deps.append(dep)
-				return 1
-			self._unsatisfied_deps_for_display.append(
-				((dep.root, dep.atom), {"myparent":dep.parent}))
-			return 0
-		# In some cases, dep_check will return deps that shouldn't
-		# be proccessed any further, so they are identified and
-		# discarded here. Try to discard as few as possible since
-		# discarded dependencies reduce the amount of information
-		# available for optimization of merge order.
-		if dep.priority.satisfied and \
-			not dep_pkg.installed and \
-			not (existing_node or empty or deep or update):
-			myarg = None
-			if dep.root == self.target_root:
-				try:
-					myarg = self._iter_atoms_for_pkg(dep_pkg).next()
-				except StopIteration:
-					pass
-				except portage.exception.InvalidDependString:
-					if not dep_pkg.installed:
-						# This shouldn't happen since the package
-						# should have been masked.
-						raise
-			if not myarg:
-				self._ignored_deps.append(dep)
-				return 1
-
-		if not self._add_pkg(dep_pkg, dep):
-			return 0
-		return 1
-
-	def _add_pkg(self, pkg, dep):
-		myparent = None
-		priority = None
-		depth = 0
-		if dep is None:
-			dep = Dependency()
-		else:
-			myparent = dep.parent
-			priority = dep.priority
-			depth = dep.depth
-		if priority is None:
-			priority = DepPriority()
-		"""
-		Fills the digraph with nodes comprised of packages to merge.
-		mybigkey is the package spec of the package to merge.
-		myparent is the package depending on mybigkey ( or None )
-		addme = Should we add this package to the digraph or are we just looking at it's deps?
-			Think --onlydeps, we need to ignore packages in that case.
-		#stuff to add:
-		#SLOT-aware emerge
-		#IUSE-aware emerge -> USE DEP aware depgraph
-		#"no downgrade" emerge
-		"""
-		# Ensure that the dependencies of the same package
-		# are never processed more than once.
-		previously_added = pkg in self.digraph
-
-		# select the correct /var database that we'll be checking against
-		vardbapi = self.trees[pkg.root]["vartree"].dbapi
-		pkgsettings = self.pkgsettings[pkg.root]
-
-		arg_atoms = None
-		if True:
-			try:
-				arg_atoms = list(self._iter_atoms_for_pkg(pkg))
-			except portage.exception.InvalidDependString, e:
-				if not pkg.installed:
-					show_invalid_depstring_notice(
-						pkg, pkg.metadata["PROVIDE"], str(e))
-					return 0
-				del e
-
-		if not pkg.onlydeps:
-			if not pkg.installed and \
-				"empty" not in self.myparams and \
-				vardbapi.match(pkg.slot_atom):
-				# Increase the priority of dependencies on packages that
-				# are being rebuilt. This optimizes merge order so that
-				# dependencies are rebuilt/updated as soon as possible,
-				# which is needed especially when emerge is called by
-				# revdep-rebuild since dependencies may be affected by ABI
-				# breakage that has rendered them useless. Don't adjust
-				# priority here when in "empty" mode since all packages
-				# are being merged in that case.
-				priority.rebuild = True
-
-			existing_node = self._slot_pkg_map[pkg.root].get(pkg.slot_atom)
-			slot_collision = False
-			if existing_node:
-				existing_node_matches = pkg.cpv == existing_node.cpv
-				if existing_node_matches and \
-					pkg != existing_node and \
-					dep.atom is not None:
-					# Use package set for matching since it will match via
-					# PROVIDE when necessary, while match_from_list does not.
-					atom_set = InternalPackageSet(initial_atoms=[dep.atom])
-					if not atom_set.findAtomForPackage(existing_node):
-						existing_node_matches = False
-				if existing_node_matches:
-					# The existing node can be reused.
-					if arg_atoms:
-						for parent_atom in arg_atoms:
-							parent, atom = parent_atom
-							self.digraph.add(existing_node, parent,
-								priority=priority)
-							self._add_parent_atom(existing_node, parent_atom)
-					# If a direct circular dependency is not an unsatisfied
-					# buildtime dependency then drop it here since otherwise
-					# it can skew the merge order calculation in an unwanted
-					# way.
-					if existing_node != myparent or \
-						(priority.buildtime and not priority.satisfied):
-						self.digraph.addnode(existing_node, myparent,
-							priority=priority)
-						if dep.atom is not None and dep.parent is not None:
-							self._add_parent_atom(existing_node,
-								(dep.parent, dep.atom))
-					return 1
-				else:
-
-					# A slot collision has occurred.  Sometimes this coincides
-					# with unresolvable blockers, so the slot collision will be
-					# shown later if there are no unresolvable blockers.
-					self._add_slot_conflict(pkg)
-					slot_collision = True
-
-			if slot_collision:
-				# Now add this node to the graph so that self.display()
-				# can show use flags and --tree portage.output.  This node is
-				# only being partially added to the graph.  It must not be
-				# allowed to interfere with the other nodes that have been
-				# added.  Do not overwrite data for existing nodes in
-				# self.mydbapi since that data will be used for blocker
-				# validation.
-				# Even though the graph is now invalid, continue to process
-				# dependencies so that things like --fetchonly can still
-				# function despite collisions.
-				pass
-			elif not previously_added:
-				self._slot_pkg_map[pkg.root][pkg.slot_atom] = pkg
-				self.mydbapi[pkg.root].cpv_inject(pkg)
-				self._filtered_trees[pkg.root]["porttree"].dbapi._clear_cache()
-
-			if not pkg.installed:
-				# Allow this package to satisfy old-style virtuals in case it
-				# doesn't already. Any pre-existing providers will be preferred
-				# over this one.
-				try:
-					pkgsettings.setinst(pkg.cpv, pkg.metadata)
-					# For consistency, also update the global virtuals.
-					settings = self.roots[pkg.root].settings
-					settings.unlock()
-					settings.setinst(pkg.cpv, pkg.metadata)
-					settings.lock()
-				except portage.exception.InvalidDependString, e:
-					show_invalid_depstring_notice(
-						pkg, pkg.metadata["PROVIDE"], str(e))
-					del e
-					return 0
-
-		if arg_atoms:
-			self._set_nodes.add(pkg)
-
-		# Do this even when addme is False (--onlydeps) so that the
-		# parent/child relationship is always known in case
-		# self._show_slot_collision_notice() needs to be called later.
-		self.digraph.add(pkg, myparent, priority=priority)
-		if dep.atom is not None and dep.parent is not None:
-			self._add_parent_atom(pkg, (dep.parent, dep.atom))
-
-		if arg_atoms:
-			for parent_atom in arg_atoms:
-				parent, atom = parent_atom
-				self.digraph.add(pkg, parent, priority=priority)
-				self._add_parent_atom(pkg, parent_atom)
-
-		""" This section determines whether we go deeper into dependencies or not.
-		    We want to go deeper on a few occasions:
-		    Installing package A, we need to make sure package A's deps are met.
-		    emerge --deep <pkgspec>; we need to recursively check dependencies of pkgspec
-		    If we are in --nodeps (no recursion) mode, we obviously only check 1 level of dependencies.
-		"""
-		dep_stack = self._dep_stack
-		if "recurse" not in self.myparams:
-			return 1
-		elif pkg.installed and \
-			"deep" not in self.myparams:
-			dep_stack = self._ignored_deps
-
-		self.spinner.update()
-
-		if arg_atoms:
-			depth = 0
-		pkg.depth = depth
-		if not previously_added:
-			dep_stack.append(pkg)
-		return 1
-
-	def _add_parent_atom(self, pkg, parent_atom):
-		parent_atoms = self._parent_atoms.get(pkg)
-		if parent_atoms is None:
-			parent_atoms = set()
-			self._parent_atoms[pkg] = parent_atoms
-		parent_atoms.add(parent_atom)
-
-	def _add_slot_conflict(self, pkg):
-		self._slot_collision_nodes.add(pkg)
-		slot_key = (pkg.slot_atom, pkg.root)
-		slot_nodes = self._slot_collision_info.get(slot_key)
-		if slot_nodes is None:
-			slot_nodes = set()
-			slot_nodes.add(self._slot_pkg_map[pkg.root][pkg.slot_atom])
-			self._slot_collision_info[slot_key] = slot_nodes
-		slot_nodes.add(pkg)
-
-	def _add_pkg_deps(self, pkg, allow_unsatisfied=False):
-
-		mytype = pkg.type_name
-		myroot = pkg.root
-		mykey = pkg.cpv
-		metadata = pkg.metadata
-		myuse = pkg.use.enabled
-		jbigkey = pkg
-		depth = pkg.depth + 1
-		removal_action = "remove" in self.myparams
-
-		edepend={}
-		depkeys = ["DEPEND","RDEPEND","PDEPEND"]
-		for k in depkeys:
-			edepend[k] = metadata[k]
-
-		if not pkg.built and \
-			"--buildpkgonly" in self.myopts and \
-			"deep" not in self.myparams and \
-			"empty" not in self.myparams:
-			edepend["RDEPEND"] = ""
-			edepend["PDEPEND"] = ""
-		bdeps_optional = False
-
-		if pkg.built and not removal_action:
-			if self.myopts.get("--with-bdeps", "n") == "y":
-				# Pull in build time deps as requested, but marked them as
-				# "optional" since they are not strictly required. This allows
-				# more freedom in the merge order calculation for solving
-				# circular dependencies. Don't convert to PDEPEND since that
-				# could make --with-bdeps=y less effective if it is used to
-				# adjust merge order to prevent built_with_use() calls from
-				# failing.
-				bdeps_optional = True
-			else:
-				# built packages do not have build time dependencies.
-				edepend["DEPEND"] = ""
-
-		if removal_action and self.myopts.get("--with-bdeps", "y") == "n":
-			edepend["DEPEND"] = ""
-
-		bdeps_root = "/"
-		root_deps = self.myopts.get("--root-deps")
-		if root_deps is not None:
-			if root_deps is True:
-				bdeps_root = myroot
-			elif root_deps == "rdeps":
-				edepend["DEPEND"] = ""
-
-		deps = (
-			(bdeps_root, edepend["DEPEND"],
-				self._priority(buildtime=(not bdeps_optional),
-				optional=bdeps_optional)),
-			(myroot, edepend["RDEPEND"], self._priority(runtime=True)),
-			(myroot, edepend["PDEPEND"], self._priority(runtime_post=True))
-		)
-
-		debug = "--debug" in self.myopts
-		strict = mytype != "installed"
-		try:
-			if not strict:
-				portage.dep._dep_check_strict = False
-
-			for dep_root, dep_string, dep_priority in deps:
-				if not dep_string:
-					continue
-				if debug:
-					print
-					print "Parent:   ", jbigkey
-					print "Depstring:", dep_string
-					print "Priority:", dep_priority
-
-				try:
-
-					dep_string = portage.dep.paren_normalize(
-						portage.dep.use_reduce(
-						portage.dep.paren_reduce(dep_string),
-						uselist=pkg.use.enabled))
-
-					dep_string = list(self._queue_disjunctive_deps(
-						pkg, dep_root, dep_priority, dep_string))
-
-				except portage.exception.InvalidDependString, e:
-					if pkg.installed:
-						del e
-						continue
-					show_invalid_depstring_notice(pkg, dep_string, str(e))
-					return 0
-
-				if not dep_string:
-					continue
-
-				dep_string = portage.dep.paren_enclose(dep_string)
-
-				if not self._add_pkg_dep_string(
-					pkg, dep_root, dep_priority, dep_string,
-					allow_unsatisfied):
-					return 0
-
-		except portage.exception.AmbiguousPackageName, e:
-			pkgs = e.args[0]
-			portage.writemsg("\n\n!!! An atom in the dependencies " + \
-				"is not fully-qualified. Multiple matches:\n\n", noiselevel=-1)
-			for cpv in pkgs:
-				portage.writemsg("    %s\n" % cpv, noiselevel=-1)
-			portage.writemsg("\n", noiselevel=-1)
-			if mytype == "binary":
-				portage.writemsg(
-					"!!! This binary package cannot be installed: '%s'\n" % \
-					mykey, noiselevel=-1)
-			elif mytype == "ebuild":
-				portdb = self.roots[myroot].trees["porttree"].dbapi
-				myebuild, mylocation = portdb.findname2(mykey)
-				portage.writemsg("!!! This ebuild cannot be installed: " + \
-					"'%s'\n" % myebuild, noiselevel=-1)
-			portage.writemsg("!!! Please notify the package maintainer " + \
-				"that atoms must be fully-qualified.\n", noiselevel=-1)
-			return 0
-		finally:
-			portage.dep._dep_check_strict = True
-		return 1
-
-	def _add_pkg_dep_string(self, pkg, dep_root, dep_priority, dep_string,
-		allow_unsatisfied):
-		depth = pkg.depth + 1
-		debug = "--debug" in self.myopts
-		strict = pkg.type_name != "installed"
-
-		if debug:
-			print
-			print "Parent:   ", pkg
-			print "Depstring:", dep_string
-			print "Priority:", dep_priority
-
-		try:
-			selected_atoms = self._select_atoms(dep_root,
-				dep_string, myuse=pkg.use.enabled, parent=pkg,
-				strict=strict, priority=dep_priority)
-		except portage.exception.InvalidDependString, e:
-			show_invalid_depstring_notice(pkg, dep_string, str(e))
-			del e
-			if pkg.installed:
-				return 1
-			return 0
-
-		if debug:
-			print "Candidates:", selected_atoms
-
-		vardb = self.roots[dep_root].trees["vartree"].dbapi
-
-		for atom in selected_atoms:
-			try:
-
-				atom = portage.dep.Atom(atom)
-
-				mypriority = dep_priority.copy()
-				if not atom.blocker and vardb.match(atom):
-					mypriority.satisfied = True
-
-				if not self._add_dep(Dependency(atom=atom,
-					blocker=atom.blocker, depth=depth, parent=pkg,
-					priority=mypriority, root=dep_root),
-					allow_unsatisfied=allow_unsatisfied):
-					return 0
-
-			except portage.exception.InvalidAtom, e:
-				show_invalid_depstring_notice(
-					pkg, dep_string, str(e))
-				del e
-				if not pkg.installed:
-					return 0
-
-		if debug:
-			print "Exiting...", pkg
-
-		return 1
-
-	def _queue_disjunctive_deps(self, pkg, dep_root, dep_priority, dep_struct):
-		"""
-		Queue disjunctive (virtual and ||) deps in self._dep_disjunctive_stack.
-		Yields non-disjunctive deps. Raises InvalidDependString when 
-		necessary.
-		"""
-		i = 0
-		while i < len(dep_struct):
-			x = dep_struct[i]
-			if isinstance(x, list):
-				for y in self._queue_disjunctive_deps(
-					pkg, dep_root, dep_priority, x):
-					yield y
-			elif x == "||":
-				self._queue_disjunction(pkg, dep_root, dep_priority,
-					[ x, dep_struct[ i + 1 ] ] )
-				i += 1
-			else:
-				try:
-					x = portage.dep.Atom(x)
-				except portage.exception.InvalidAtom:
-					if not pkg.installed:
-						raise portage.exception.InvalidDependString(
-							"invalid atom: '%s'" % x)
-				else:
-					# Note: Eventually this will check for PROPERTIES=virtual
-					# or whatever other metadata gets implemented for this
-					# purpose.
-					if x.cp.startswith('virtual/'):
-						self._queue_disjunction( pkg, dep_root,
-							dep_priority, [ str(x) ] )
-					else:
-						yield str(x)
-			i += 1
-
-	def _queue_disjunction(self, pkg, dep_root, dep_priority, dep_struct):
-		self._dep_disjunctive_stack.append(
-			(pkg, dep_root, dep_priority, dep_struct))
-
-	def _pop_disjunction(self, allow_unsatisfied):
-		"""
-		Pop one disjunctive dep from self._dep_disjunctive_stack, and use it to
-		populate self._dep_stack.
-		"""
-		pkg, dep_root, dep_priority, dep_struct = \
-			self._dep_disjunctive_stack.pop()
-		dep_string = portage.dep.paren_enclose(dep_struct)
-		if not self._add_pkg_dep_string(
-			pkg, dep_root, dep_priority, dep_string, allow_unsatisfied):
-			return 0
-		return 1
-
-	def _priority(self, **kwargs):
-		if "remove" in self.myparams:
-			priority_constructor = UnmergeDepPriority
-		else:
-			priority_constructor = DepPriority
-		return priority_constructor(**kwargs)
-
-	def _dep_expand(self, root_config, atom_without_category):
-		"""
-		@param root_config: a root config instance
-		@type root_config: RootConfig
-		@param atom_without_category: an atom without a category component
-		@type atom_without_category: String
-		@rtype: list
-		@returns: a list of atoms containing categories (possibly empty)
-		"""
-		null_cp = portage.dep_getkey(insert_category_into_atom(
-			atom_without_category, "null"))
-		cat, atom_pn = portage.catsplit(null_cp)
-
-		dbs = self._filtered_trees[root_config.root]["dbs"]
-		categories = set()
-		for db, pkg_type, built, installed, db_keys in dbs:
-			for cat in db.categories:
-				if db.cp_list("%s/%s" % (cat, atom_pn)):
-					categories.add(cat)
-
-		deps = []
-		for cat in categories:
-			deps.append(insert_category_into_atom(
-				atom_without_category, cat))
-		return deps
-
-	def _have_new_virt(self, root, atom_cp):
-		ret = False
-		for db, pkg_type, built, installed, db_keys in \
-			self._filtered_trees[root]["dbs"]:
-			if db.cp_list(atom_cp):
-				ret = True
-				break
-		return ret
-
-	def _iter_atoms_for_pkg(self, pkg):
-		# TODO: add multiple $ROOT support
-		if pkg.root != self.target_root:
-			return
-		atom_arg_map = self._atom_arg_map
-		root_config = self.roots[pkg.root]
-		for atom in self._set_atoms.iterAtomsForPackage(pkg):
-			atom_cp = portage.dep_getkey(atom)
-			if atom_cp != pkg.cp and \
-				self._have_new_virt(pkg.root, atom_cp):
-				continue
-			visible_pkgs = root_config.visible_pkgs.match_pkgs(atom)
-			visible_pkgs.reverse() # descending order
-			higher_slot = None
-			for visible_pkg in visible_pkgs:
-				if visible_pkg.cp != atom_cp:
-					continue
-				if pkg >= visible_pkg:
-					# This is descending order, and we're not
-					# interested in any versions <= pkg given.
-					break
-				if pkg.slot_atom != visible_pkg.slot_atom:
-					higher_slot = visible_pkg
-					break
-			if higher_slot is not None:
-				continue
-			for arg in atom_arg_map[(atom, pkg.root)]:
-				if isinstance(arg, PackageArg) and \
-					arg.package != pkg:
-					continue
-				yield arg, atom
-
-	def select_files(self, myfiles):
-		"""Given a list of .tbz2s, .ebuilds sets, and deps, create the
-		appropriate depgraph and return a favorite list."""
-		debug = "--debug" in self.myopts
-		root_config = self.roots[self.target_root]
-		sets = root_config.sets
-		getSetAtoms = root_config.setconfig.getSetAtoms
-		myfavorites=[]
-		myroot = self.target_root
-		dbs = self._filtered_trees[myroot]["dbs"]
-		vardb = self.trees[myroot]["vartree"].dbapi
-		real_vardb = self._trees_orig[myroot]["vartree"].dbapi
-		portdb = self.trees[myroot]["porttree"].dbapi
-		bindb = self.trees[myroot]["bintree"].dbapi
-		pkgsettings = self.pkgsettings[myroot]
-		args = []
-		onlydeps = "--onlydeps" in self.myopts
-		lookup_owners = []
-		for x in myfiles:
-			ext = os.path.splitext(x)[1]
-			if ext==".tbz2":
-				if not os.path.exists(x):
-					if os.path.exists(
-						os.path.join(pkgsettings["PKGDIR"], "All", x)):
-						x = os.path.join(pkgsettings["PKGDIR"], "All", x)
-					elif os.path.exists(
-						os.path.join(pkgsettings["PKGDIR"], x)):
-						x = os.path.join(pkgsettings["PKGDIR"], x)
-					else:
-						print "\n\n!!! Binary package '"+str(x)+"' does not exist."
-						print "!!! Please ensure the tbz2 exists as specified.\n"
-						return 0, myfavorites
-				mytbz2=portage.xpak.tbz2(x)
-				mykey=mytbz2.getelements("CATEGORY")[0]+"/"+os.path.splitext(os.path.basename(x))[0]
-				if os.path.realpath(x) != \
-					os.path.realpath(self.trees[myroot]["bintree"].getname(mykey)):
-					print colorize("BAD", "\n*** You need to adjust PKGDIR to emerge this package.\n")
-					return 0, myfavorites
-				db_keys = list(bindb._aux_cache_keys)
-				metadata = izip(db_keys, bindb.aux_get(mykey, db_keys))
-				pkg = Package(type_name="binary", root_config=root_config,
-					cpv=mykey, built=True, metadata=metadata,
-					onlydeps=onlydeps)
-				self._pkg_cache[pkg] = pkg
-				args.append(PackageArg(arg=x, package=pkg,
-					root_config=root_config))
-			elif ext==".ebuild":
-				ebuild_path = portage.util.normalize_path(os.path.abspath(x))
-				pkgdir = os.path.dirname(ebuild_path)
-				tree_root = os.path.dirname(os.path.dirname(pkgdir))
-				cp = pkgdir[len(tree_root)+1:]
-				e = portage.exception.PackageNotFound(
-					("%s is not in a valid portage tree " + \
-					"hierarchy or does not exist") % x)
-				if not portage.isvalidatom(cp):
-					raise e
-				cat = portage.catsplit(cp)[0]
-				mykey = cat + "/" + os.path.basename(ebuild_path[:-7])
-				if not portage.isvalidatom("="+mykey):
-					raise e
-				ebuild_path = portdb.findname(mykey)
-				if ebuild_path:
-					if ebuild_path != os.path.join(os.path.realpath(tree_root),
-						cp, os.path.basename(ebuild_path)):
-						print colorize("BAD", "\n*** You need to adjust PORTDIR or PORTDIR_OVERLAY to emerge this package.\n")
-						return 0, myfavorites
-					if mykey not in portdb.xmatch(
-						"match-visible", portage.dep_getkey(mykey)):
-						print colorize("BAD", "\n*** You are emerging a masked package. It is MUCH better to use")
-						print colorize("BAD", "*** /etc/portage/package.* to accomplish this. See portage(5) man")
-						print colorize("BAD", "*** page for details.")
-						countdown(int(self.settings["EMERGE_WARNING_DELAY"]),
-							"Continuing...")
-				else:
-					raise portage.exception.PackageNotFound(
-						"%s is not in a valid portage tree hierarchy or does not exist" % x)
-				db_keys = list(portdb._aux_cache_keys)
-				metadata = izip(db_keys, portdb.aux_get(mykey, db_keys))
-				pkg = Package(type_name="ebuild", root_config=root_config,
-					cpv=mykey, metadata=metadata, onlydeps=onlydeps)
-				pkgsettings.setcpv(pkg)
-				pkg.metadata["USE"] = pkgsettings["PORTAGE_USE"]
-				pkg.metadata['CHOST'] = pkgsettings.get('CHOST', '')
-				self._pkg_cache[pkg] = pkg
-				args.append(PackageArg(arg=x, package=pkg,
-					root_config=root_config))
-			elif x.startswith(os.path.sep):
-				if not x.startswith(myroot):
-					portage.writemsg(("\n\n!!! '%s' does not start with" + \
-						" $ROOT.\n") % x, noiselevel=-1)
-					return 0, []
-				# Queue these up since it's most efficient to handle
-				# multiple files in a single iter_owners() call.
-				lookup_owners.append(x)
-			else:
-				if x in ("system", "world"):
-					x = SETPREFIX + x
-				if x.startswith(SETPREFIX):
-					s = x[len(SETPREFIX):]
-					if s not in sets:
-						raise portage.exception.PackageSetNotFound(s)
-					if s in self._sets:
-						continue
-					# Recursively expand sets so that containment tests in
-					# self._get_parent_sets() properly match atoms in nested
-					# sets (like if world contains system).
-					expanded_set = InternalPackageSet(
-						initial_atoms=getSetAtoms(s))
-					self._sets[s] = expanded_set
-					args.append(SetArg(arg=x, set=expanded_set,
-						root_config=root_config))
-					continue
-				if not is_valid_package_atom(x):
-					portage.writemsg("\n\n!!! '%s' is not a valid package atom.\n" % x,
-						noiselevel=-1)
-					portage.writemsg("!!! Please check ebuild(5) for full details.\n")
-					portage.writemsg("!!! (Did you specify a version but forget to prefix with '='?)\n")
-					return (0,[])
-				# Don't expand categories or old-style virtuals here unless
-				# necessary. Expansion of old-style virtuals here causes at
-				# least the following problems:
-				#   1) It's more difficult to determine which set(s) an atom
-				#      came from, if any.
-				#   2) It takes away freedom from the resolver to choose other
-				#      possible expansions when necessary.
-				if "/" in x:
-					args.append(AtomArg(arg=x, atom=x,
-						root_config=root_config))
-					continue
-				expanded_atoms = self._dep_expand(root_config, x)
-				installed_cp_set = set()
-				for atom in expanded_atoms:
-					atom_cp = portage.dep_getkey(atom)
-					if vardb.cp_list(atom_cp):
-						installed_cp_set.add(atom_cp)
-
-				if len(installed_cp_set) > 1:
-					non_virtual_cps = set()
-					for atom_cp in installed_cp_set:
-						if not atom_cp.startswith("virtual/"):
-							non_virtual_cps.add(atom_cp)
-					if len(non_virtual_cps) == 1:
-						installed_cp_set = non_virtual_cps
-
-				if len(expanded_atoms) > 1 and len(installed_cp_set) == 1:
-					installed_cp = iter(installed_cp_set).next()
-					expanded_atoms = [atom for atom in expanded_atoms \
-						if portage.dep_getkey(atom) == installed_cp]
-
-				if len(expanded_atoms) > 1:
-					print
-					print
-					ambiguous_package_name(x, expanded_atoms, root_config,
-						self.spinner, self.myopts)
-					return False, myfavorites
-				if expanded_atoms:
-					atom = expanded_atoms[0]
-				else:
-					null_atom = insert_category_into_atom(x, "null")
-					null_cp = portage.dep_getkey(null_atom)
-					cat, atom_pn = portage.catsplit(null_cp)
-					virts_p = root_config.settings.get_virts_p().get(atom_pn)
-					if virts_p:
-						# Allow the depgraph to choose which virtual.
-						atom = insert_category_into_atom(x, "virtual")
-					else:
-						atom = insert_category_into_atom(x, "null")
-
-				args.append(AtomArg(arg=x, atom=atom,
-					root_config=root_config))
-
-		if lookup_owners:
-			relative_paths = []
-			search_for_multiple = False
-			if len(lookup_owners) > 1:
-				search_for_multiple = True
-
-			for x in lookup_owners:
-				if not search_for_multiple and os.path.isdir(x):
-					search_for_multiple = True
-				relative_paths.append(x[len(myroot):])
-
-			owners = set()
-			for pkg, relative_path in \
-				real_vardb._owners.iter_owners(relative_paths):
-				owners.add(pkg.mycpv)
-				if not search_for_multiple:
-					break
-
-			if not owners:
-				portage.writemsg(("\n\n!!! '%s' is not claimed " + \
-					"by any package.\n") % lookup_owners[0], noiselevel=-1)
-				return 0, []
-
-			for cpv in owners:
-				slot = vardb.aux_get(cpv, ["SLOT"])[0]
-				if not slot:
-					# portage now masks packages with missing slot, but it's
-					# possible that one was installed by an older version
-					atom = portage.cpv_getkey(cpv)
-				else:
-					atom = "%s:%s" % (portage.cpv_getkey(cpv), slot)
-				args.append(AtomArg(arg=atom, atom=atom,
-					root_config=root_config))
-
-		if "--update" in self.myopts:
-			# In some cases, the greedy slots behavior can pull in a slot that
-			# the user would want to uninstall due to it being blocked by a
-			# newer version in a different slot. Therefore, it's necessary to
-			# detect and discard any that should be uninstalled. Each time
-			# that arguments are updated, package selections are repeated in
-			# order to ensure consistency with the current arguments:
-			#
-			#  1) Initialize args
-			#  2) Select packages and generate initial greedy atoms
-			#  3) Update args with greedy atoms
-			#  4) Select packages and generate greedy atoms again, while
-			#     accounting for any blockers between selected packages
-			#  5) Update args with revised greedy atoms
-
-			self._set_args(args)
-			greedy_args = []
-			for arg in args:
-				greedy_args.append(arg)
-				if not isinstance(arg, AtomArg):
-					continue
-				for atom in self._greedy_slots(arg.root_config, arg.atom):
-					greedy_args.append(
-						AtomArg(arg=arg.arg, atom=atom,
-							root_config=arg.root_config))
-
-			self._set_args(greedy_args)
-			del greedy_args
-
-			# Revise greedy atoms, accounting for any blockers
-			# between selected packages.
-			revised_greedy_args = []
-			for arg in args:
-				revised_greedy_args.append(arg)
-				if not isinstance(arg, AtomArg):
-					continue
-				for atom in self._greedy_slots(arg.root_config, arg.atom,
-					blocker_lookahead=True):
-					revised_greedy_args.append(
-						AtomArg(arg=arg.arg, atom=atom,
-							root_config=arg.root_config))
-			args = revised_greedy_args
-			del revised_greedy_args
-
-		self._set_args(args)
-
-		myfavorites = set(myfavorites)
-		for arg in args:
-			if isinstance(arg, (AtomArg, PackageArg)):
-				myfavorites.add(arg.atom)
-			elif isinstance(arg, SetArg):
-				myfavorites.add(arg.arg)
-		myfavorites = list(myfavorites)
-
-		pprovideddict = pkgsettings.pprovideddict
-		if debug:
-			portage.writemsg("\n", noiselevel=-1)
-		# Order needs to be preserved since a feature of --nodeps
-		# is to allow the user to force a specific merge order.
-		args.reverse()
-		while args:
-			arg = args.pop()
-			for atom in arg.set:
-				self.spinner.update()
-				dep = Dependency(atom=atom, onlydeps=onlydeps,
-					root=myroot, parent=arg)
-				atom_cp = portage.dep_getkey(atom)
-				try:
-					pprovided = pprovideddict.get(portage.dep_getkey(atom))
-					if pprovided and portage.match_from_list(atom, pprovided):
-						# A provided package has been specified on the command line.
-						self._pprovided_args.append((arg, atom))
-						continue
-					if isinstance(arg, PackageArg):
-						if not self._add_pkg(arg.package, dep) or \
-							not self._create_graph():
-							sys.stderr.write(("\n\n!!! Problem resolving " + \
-								"dependencies for %s\n") % arg.arg)
-							return 0, myfavorites
-						continue
-					if debug:
-						portage.writemsg("      Arg: %s\n     Atom: %s\n" % \
-							(arg, atom), noiselevel=-1)
-					pkg, existing_node = self._select_package(
-						myroot, atom, onlydeps=onlydeps)
-					if not pkg:
-						if not (isinstance(arg, SetArg) and \
-							arg.name in ("system", "world")):
-							self._unsatisfied_deps_for_display.append(
-								((myroot, atom), {}))
-							return 0, myfavorites
-						self._missing_args.append((arg, atom))
-						continue
-					if atom_cp != pkg.cp:
-						# For old-style virtuals, we need to repeat the
-						# package.provided check against the selected package.
-						expanded_atom = atom.replace(atom_cp, pkg.cp)
-						pprovided = pprovideddict.get(pkg.cp)
-						if pprovided and \
-							portage.match_from_list(expanded_atom, pprovided):
-							# A provided package has been
-							# specified on the command line.
-							self._pprovided_args.append((arg, atom))
-							continue
-					if pkg.installed and "selective" not in self.myparams:
-						self._unsatisfied_deps_for_display.append(
-							((myroot, atom), {}))
-						# Previous behavior was to bail out in this case, but
-						# since the dep is satisfied by the installed package,
-						# it's more friendly to continue building the graph
-						# and just show a warning message. Therefore, only bail
-						# out here if the atom is not from either the system or
-						# world set.
-						if not (isinstance(arg, SetArg) and \
-							arg.name in ("system", "world")):
-							return 0, myfavorites
-
-					# Add the selected package to the graph as soon as possible
-					# so that later dep_check() calls can use it as feedback
-					# for making more consistent atom selections.
-					if not self._add_pkg(pkg, dep):
-						if isinstance(arg, SetArg):
-							sys.stderr.write(("\n\n!!! Problem resolving " + \
-								"dependencies for %s from %s\n") % \
-								(atom, arg.arg))
-						else:
-							sys.stderr.write(("\n\n!!! Problem resolving " + \
-								"dependencies for %s\n") % atom)
-						return 0, myfavorites
-
-				except portage.exception.MissingSignature, e:
-					portage.writemsg("\n\n!!! A missing gpg signature is preventing portage from calculating the\n")
-					portage.writemsg("!!! required dependencies. This is a security feature enabled by the admin\n")
-					portage.writemsg("!!! to aid in the detection of malicious intent.\n\n")
-					portage.writemsg("!!! THIS IS A POSSIBLE INDICATION OF TAMPERED FILES -- CHECK CAREFULLY.\n")
-					portage.writemsg("!!! Affected file: %s\n" % (e), noiselevel=-1)
-					return 0, myfavorites
-				except portage.exception.InvalidSignature, e:
-					portage.writemsg("\n\n!!! An invalid gpg signature is preventing portage from calculating the\n")
-					portage.writemsg("!!! required dependencies. This is a security feature enabled by the admin\n")
-					portage.writemsg("!!! to aid in the detection of malicious intent.\n\n")
-					portage.writemsg("!!! THIS IS A POSSIBLE INDICATION OF TAMPERED FILES -- CHECK CAREFULLY.\n")
-					portage.writemsg("!!! Affected file: %s\n" % (e), noiselevel=-1)
-					return 0, myfavorites
-				except SystemExit, e:
-					raise # Needed else can't exit
-				except Exception, e:
-					print >> sys.stderr, "\n\n!!! Problem in '%s' dependencies." % atom
-					print >> sys.stderr, "!!!", str(e), getattr(e, "__module__", None)
-					raise
-
-		# Now that the root packages have been added to the graph,
-		# process the dependencies.
-		if not self._create_graph():
-			return 0, myfavorites
-
-		missing=0
-		if "--usepkgonly" in self.myopts:
-			for xs in self.digraph.all_nodes():
-				if not isinstance(xs, Package):
-					continue
-				if len(xs) >= 4 and xs[0] != "binary" and xs[3] == "merge":
-					if missing == 0:
-						print
-					missing += 1
-					print "Missing binary for:",xs[2]
-
-		try:
-			self.altlist()
-		except self._unknown_internal_error:
-			return False, myfavorites
-
-		# We're true here unless we are missing binaries.
-		return (not missing,myfavorites)
-
-	def _set_args(self, args):
-		"""
-		Create the "args" package set from atoms and packages given as
-		arguments. This method can be called multiple times if necessary.
-		The package selection cache is automatically invalidated, since
-		arguments influence package selections.
-		"""
-		args_set = self._sets["args"]
-		args_set.clear()
-		for arg in args:
-			if not isinstance(arg, (AtomArg, PackageArg)):
-				continue
-			atom = arg.atom
-			if atom in args_set:
-				continue
-			args_set.add(atom)
-
-		self._set_atoms.clear()
-		self._set_atoms.update(chain(*self._sets.itervalues()))
-		atom_arg_map = self._atom_arg_map
-		atom_arg_map.clear()
-		for arg in args:
-			for atom in arg.set:
-				atom_key = (atom, arg.root_config.root)
-				refs = atom_arg_map.get(atom_key)
-				if refs is None:
-					refs = []
-					atom_arg_map[atom_key] = refs
-					if arg not in refs:
-						refs.append(arg)
-
-		# Invalidate the package selection cache, since
-		# arguments influence package selections.
-		self._highest_pkg_cache.clear()
-		for trees in self._filtered_trees.itervalues():
-			trees["porttree"].dbapi._clear_cache()
-
-	def _greedy_slots(self, root_config, atom, blocker_lookahead=False):
-		"""
-		Return a list of slot atoms corresponding to installed slots that
-		differ from the slot of the highest visible match. When
-		blocker_lookahead is True, slot atoms that would trigger a blocker
-		conflict are automatically discarded, potentially allowing automatic
-		uninstallation of older slots when appropriate.
-		"""
-		highest_pkg, in_graph = self._select_package(root_config.root, atom)
-		if highest_pkg is None:
-			return []
-		vardb = root_config.trees["vartree"].dbapi
-		slots = set()
-		for cpv in vardb.match(atom):
-			# don't mix new virtuals with old virtuals
-			if portage.cpv_getkey(cpv) == highest_pkg.cp:
-				slots.add(vardb.aux_get(cpv, ["SLOT"])[0])
-
-		slots.add(highest_pkg.metadata["SLOT"])
-		if len(slots) == 1:
-			return []
-		greedy_pkgs = []
-		slots.remove(highest_pkg.metadata["SLOT"])
-		while slots:
-			slot = slots.pop()
-			slot_atom = portage.dep.Atom("%s:%s" % (highest_pkg.cp, slot))
-			pkg, in_graph = self._select_package(root_config.root, slot_atom)
-			if pkg is not None and \
-				pkg.cp == highest_pkg.cp and pkg < highest_pkg:
-				greedy_pkgs.append(pkg)
-		if not greedy_pkgs:
-			return []
-		if not blocker_lookahead:
-			return [pkg.slot_atom for pkg in greedy_pkgs]
-
-		blockers = {}
-		blocker_dep_keys = ["DEPEND", "PDEPEND", "RDEPEND"]
-		for pkg in greedy_pkgs + [highest_pkg]:
-			dep_str = " ".join(pkg.metadata[k] for k in blocker_dep_keys)
-			try:
-				atoms = self._select_atoms(
-					pkg.root, dep_str, pkg.use.enabled,
-					parent=pkg, strict=True)
-			except portage.exception.InvalidDependString:
-				continue
-			blocker_atoms = (x for x in atoms if x.blocker)
-			blockers[pkg] = InternalPackageSet(initial_atoms=blocker_atoms)
-
-		if highest_pkg not in blockers:
-			return []
-
-		# filter packages with invalid deps
-		greedy_pkgs = [pkg for pkg in greedy_pkgs if pkg in blockers]
-
-		# filter packages that conflict with highest_pkg
-		greedy_pkgs = [pkg for pkg in greedy_pkgs if not \
-			(blockers[highest_pkg].findAtomForPackage(pkg) or \
-			blockers[pkg].findAtomForPackage(highest_pkg))]
-
-		if not greedy_pkgs:
-			return []
-
-		# If two packages conflict, discard the lower version.
-		discard_pkgs = set()
-		greedy_pkgs.sort(reverse=True)
-		for i in xrange(len(greedy_pkgs) - 1):
-			pkg1 = greedy_pkgs[i]
-			if pkg1 in discard_pkgs:
-				continue
-			for j in xrange(i + 1, len(greedy_pkgs)):
-				pkg2 = greedy_pkgs[j]
-				if pkg2 in discard_pkgs:
-					continue
-				if blockers[pkg1].findAtomForPackage(pkg2) or \
-					blockers[pkg2].findAtomForPackage(pkg1):
-					# pkg1 > pkg2
-					discard_pkgs.add(pkg2)
-
-		return [pkg.slot_atom for pkg in greedy_pkgs \
-			if pkg not in discard_pkgs]
-
-	def _select_atoms_from_graph(self, *pargs, **kwargs):
-		"""
-		Prefer atoms matching packages that have already been
-		added to the graph or those that are installed and have
-		not been scheduled for replacement.
-		"""
-		kwargs["trees"] = self._graph_trees
-		return self._select_atoms_highest_available(*pargs, **kwargs)
-
-	def _select_atoms_highest_available(self, root, depstring,
-		myuse=None, parent=None, strict=True, trees=None, priority=None):
-		"""This will raise InvalidDependString if necessary. If trees is
-		None then self._filtered_trees is used."""
-		pkgsettings = self.pkgsettings[root]
-		if trees is None:
-			trees = self._filtered_trees
-		if not getattr(priority, "buildtime", False):
-			# The parent should only be passed to dep_check() for buildtime
-			# dependencies since that's the only case when it's appropriate
-			# to trigger the circular dependency avoidance code which uses it.
-			# It's important not to trigger the same circular dependency
-			# avoidance code for runtime dependencies since it's not needed
-			# and it can promote an incorrect package choice.
-			parent = None
-		if True:
-			try:
-				if parent is not None:
-					trees[root]["parent"] = parent
-				if not strict:
-					portage.dep._dep_check_strict = False
-				mycheck = portage.dep_check(depstring, None,
-					pkgsettings, myuse=myuse,
-					myroot=root, trees=trees)
-			finally:
-				if parent is not None:
-					trees[root].pop("parent")
-				portage.dep._dep_check_strict = True
-			if not mycheck[0]:
-				raise portage.exception.InvalidDependString(mycheck[1])
-			selected_atoms = mycheck[1]
-		return selected_atoms
-
-	def _show_unsatisfied_dep(self, root, atom, myparent=None, arg=None):
-		atom = portage.dep.Atom(atom)
-		atom_set = InternalPackageSet(initial_atoms=(atom,))
-		atom_without_use = atom
-		if atom.use:
-			atom_without_use = portage.dep.remove_slot(atom)
-			if atom.slot:
-				atom_without_use += ":" + atom.slot
-			atom_without_use = portage.dep.Atom(atom_without_use)
-		xinfo = '"%s"' % atom
-		if arg:
-			xinfo='"%s"' % arg
-		# Discard null/ from failed cpv_expand category expansion.
-		xinfo = xinfo.replace("null/", "")
-		masked_packages = []
-		missing_use = []
-		masked_pkg_instances = set()
-		missing_licenses = []
-		have_eapi_mask = False
-		pkgsettings = self.pkgsettings[root]
-		implicit_iuse = pkgsettings._get_implicit_iuse()
-		root_config = self.roots[root]
-		portdb = self.roots[root].trees["porttree"].dbapi
-		dbs = self._filtered_trees[root]["dbs"]
-		for db, pkg_type, built, installed, db_keys in dbs:
-			if installed:
-				continue
-			match = db.match
-			if hasattr(db, "xmatch"):
-				cpv_list = db.xmatch("match-all", atom_without_use)
-			else:
-				cpv_list = db.match(atom_without_use)
-			# descending order
-			cpv_list.reverse()
-			for cpv in cpv_list:
-				metadata, mreasons  = get_mask_info(root_config, cpv,
-					pkgsettings, db, pkg_type, built, installed, db_keys)
-				if metadata is not None:
-					pkg = Package(built=built, cpv=cpv,
-						installed=installed, metadata=metadata,
-						root_config=root_config)
-					if pkg.cp != atom.cp:
-						# A cpv can be returned from dbapi.match() as an
-						# old-style virtual match even in cases when the
-						# package does not actually PROVIDE the virtual.
-						# Filter out any such false matches here.
-						if not atom_set.findAtomForPackage(pkg):
-							continue
-					if mreasons:
-						masked_pkg_instances.add(pkg)
-					if atom.use:
-						missing_use.append(pkg)
-						if not mreasons:
-							continue
-				masked_packages.append(
-					(root_config, pkgsettings, cpv, metadata, mreasons))
-
-		missing_use_reasons = []
-		missing_iuse_reasons = []
-		for pkg in missing_use:
-			use = pkg.use.enabled
-			iuse = implicit_iuse.union(re.escape(x) for x in pkg.iuse.all)
-			iuse_re = re.compile("^(%s)$" % "|".join(iuse))
-			missing_iuse = []
-			for x in atom.use.required:
-				if iuse_re.match(x) is None:
-					missing_iuse.append(x)
-			mreasons = []
-			if missing_iuse:
-				mreasons.append("Missing IUSE: %s" % " ".join(missing_iuse))
-				missing_iuse_reasons.append((pkg, mreasons))
-			else:
-				need_enable = sorted(atom.use.enabled.difference(use))
-				need_disable = sorted(atom.use.disabled.intersection(use))
-				if need_enable or need_disable:
-					changes = []
-					changes.extend(colorize("red", "+" + x) \
-						for x in need_enable)
-					changes.extend(colorize("blue", "-" + x) \
-						for x in need_disable)
-					mreasons.append("Change USE: %s" % " ".join(changes))
-					missing_use_reasons.append((pkg, mreasons))
-
-		unmasked_use_reasons = [(pkg, mreasons) for (pkg, mreasons) \
-			in missing_use_reasons if pkg not in masked_pkg_instances]
-
-		unmasked_iuse_reasons = [(pkg, mreasons) for (pkg, mreasons) \
-			in missing_iuse_reasons if pkg not in masked_pkg_instances]
-
-		show_missing_use = False
-		if unmasked_use_reasons:
-			# Only show the latest version.
-			show_missing_use = unmasked_use_reasons[:1]
-		elif unmasked_iuse_reasons:
-			if missing_use_reasons:
-				# All packages with required IUSE are masked,
-				# so display a normal masking message.
-				pass
-			else:
-				show_missing_use = unmasked_iuse_reasons
-
-		if show_missing_use:
-			print "\nemerge: there are no ebuilds built with USE flags to satisfy "+green(xinfo)+"."
-			print "!!! One of the following packages is required to complete your request:"
-			for pkg, mreasons in show_missing_use:
-				print "- "+pkg.cpv+" ("+", ".join(mreasons)+")"
-
-		elif masked_packages:
-			print "\n!!! " + \
-				colorize("BAD", "All ebuilds that could satisfy ") + \
-				colorize("INFORM", xinfo) + \
-				colorize("BAD", " have been masked.")
-			print "!!! One of the following masked packages is required to complete your request:"
-			have_eapi_mask = show_masked_packages(masked_packages)
-			if have_eapi_mask:
-				print
-				msg = ("The current version of portage supports " + \
-					"EAPI '%s'. You must upgrade to a newer version" + \
-					" of portage before EAPI masked packages can" + \
-					" be installed.") % portage.const.EAPI
-				from textwrap import wrap
-				for line in wrap(msg, 75):
-					print line
-			print
-			show_mask_docs()
-		else:
-			print "\nemerge: there are no ebuilds to satisfy "+green(xinfo)+"."
-
-		# Show parent nodes and the argument that pulled them in.
-		traversed_nodes = set()
-		node = myparent
-		msg = []
-		while node is not None:
-			traversed_nodes.add(node)
-			msg.append('(dependency required by "%s" [%s])' % \
-				(colorize('INFORM', str(node.cpv)), node.type_name))
-			# When traversing to parents, prefer arguments over packages
-			# since arguments are root nodes. Never traverse the same
-			# package twice, in order to prevent an infinite loop.
-			selected_parent = None
-			for parent in self.digraph.parent_nodes(node):
-				if isinstance(parent, DependencyArg):
-					msg.append('(dependency required by "%s" [argument])' % \
-						(colorize('INFORM', str(parent))))
-					selected_parent = None
-					break
-				if parent not in traversed_nodes:
-					selected_parent = parent
-			node = selected_parent
-		for line in msg:
-			print line
-
-		print
-
-	def _select_pkg_highest_available(self, root, atom, onlydeps=False):
-		cache_key = (root, atom, onlydeps)
-		ret = self._highest_pkg_cache.get(cache_key)
-		if ret is not None:
-			pkg, existing = ret
-			if pkg and not existing:
-				existing = self._slot_pkg_map[root].get(pkg.slot_atom)
-				if existing and existing == pkg:
-					# Update the cache to reflect that the
-					# package has been added to the graph.
-					ret = pkg, pkg
-					self._highest_pkg_cache[cache_key] = ret
-			return ret
-		ret = self._select_pkg_highest_available_imp(root, atom, onlydeps=onlydeps)
-		self._highest_pkg_cache[cache_key] = ret
-		pkg, existing = ret
-		if pkg is not None:
-			settings = pkg.root_config.settings
-			if visible(settings, pkg) and not (pkg.installed and \
-				settings._getMissingKeywords(pkg.cpv, pkg.metadata)):
-				pkg.root_config.visible_pkgs.cpv_inject(pkg)
-		return ret
-
-	def _select_pkg_highest_available_imp(self, root, atom, onlydeps=False):
-		root_config = self.roots[root]
-		pkgsettings = self.pkgsettings[root]
-		dbs = self._filtered_trees[root]["dbs"]
-		vardb = self.roots[root].trees["vartree"].dbapi
-		portdb = self.roots[root].trees["porttree"].dbapi
-		# List of acceptable packages, ordered by type preference.
-		matched_packages = []
-		highest_version = None
-		if not isinstance(atom, portage.dep.Atom):
-			atom = portage.dep.Atom(atom)
-		atom_cp = atom.cp
-		atom_set = InternalPackageSet(initial_atoms=(atom,))
-		existing_node = None
-		myeb = None
-		usepkgonly = "--usepkgonly" in self.myopts
-		empty = "empty" in self.myparams
-		selective = "selective" in self.myparams
-		reinstall = False
-		noreplace = "--noreplace" in self.myopts
-		# Behavior of the "selective" parameter depends on
-		# whether or not a package matches an argument atom.
-		# If an installed package provides an old-style
-		# virtual that is no longer provided by an available
-		# package, the installed package may match an argument
-		# atom even though none of the available packages do.
-		# Therefore, "selective" logic does not consider
-		# whether or not an installed package matches an
-		# argument atom. It only considers whether or not
-		# available packages match argument atoms, which is
-		# represented by the found_available_arg flag.
-		found_available_arg = False
-		for find_existing_node in True, False:
-			if existing_node:
-				break
-			for db, pkg_type, built, installed, db_keys in dbs:
-				if existing_node:
-					break
-				if installed and not find_existing_node:
-					want_reinstall = reinstall or empty or \
-						(found_available_arg and not selective)
-					if want_reinstall and matched_packages:
-						continue
-				if hasattr(db, "xmatch"):
-					cpv_list = db.xmatch("match-all", atom)
-				else:
-					cpv_list = db.match(atom)
-
-				# USE=multislot can make an installed package appear as if
-				# it doesn't satisfy a slot dependency. Rebuilding the ebuild
-				# won't do any good as long as USE=multislot is enabled since
-				# the newly built package still won't have the expected slot.
-				# Therefore, assume that such SLOT dependencies are already
-				# satisfied rather than forcing a rebuild.
-				if installed and not cpv_list and atom.slot:
-					for cpv in db.match(atom.cp):
-						slot_available = False
-						for other_db, other_type, other_built, \
-							other_installed, other_keys in dbs:
-							try:
-								if atom.slot == \
-									other_db.aux_get(cpv, ["SLOT"])[0]:
-									slot_available = True
-									break
-							except KeyError:
-								pass
-						if not slot_available:
-							continue
-						inst_pkg = self._pkg(cpv, "installed",
-							root_config, installed=installed)
-						# Remove the slot from the atom and verify that
-						# the package matches the resulting atom.
-						atom_without_slot = portage.dep.remove_slot(atom)
-						if atom.use:
-							atom_without_slot += str(atom.use)
-						atom_without_slot = portage.dep.Atom(atom_without_slot)
-						if portage.match_from_list(
-							atom_without_slot, [inst_pkg]):
-							cpv_list = [inst_pkg.cpv]
-						break
-
-				if not cpv_list:
-					continue
-				pkg_status = "merge"
-				if installed or onlydeps:
-					pkg_status = "nomerge"
-				# descending order
-				cpv_list.reverse()
-				for cpv in cpv_list:
-					# Make --noreplace take precedence over --newuse.
-					if not installed and noreplace and \
-						cpv in vardb.match(atom):
-						# If the installed version is masked, it may
-						# be necessary to look at lower versions,
-						# in case there is a visible downgrade.
-						continue
-					reinstall_for_flags = None
-					cache_key = (pkg_type, root, cpv, pkg_status)
-					calculated_use = True
-					pkg = self._pkg_cache.get(cache_key)
-					if pkg is None:
-						calculated_use = False
-						try:
-							metadata = izip(db_keys, db.aux_get(cpv, db_keys))
-						except KeyError:
-							continue
-						pkg = Package(built=built, cpv=cpv,
-							installed=installed, metadata=metadata,
-							onlydeps=onlydeps, root_config=root_config,
-							type_name=pkg_type)
-						metadata = pkg.metadata
-						if not built:
-							metadata['CHOST'] = pkgsettings.get('CHOST', '')
-						if not built and ("?" in metadata["LICENSE"] or \
-							"?" in metadata["PROVIDE"]):
-							# This is avoided whenever possible because
-							# it's expensive. It only needs to be done here
-							# if it has an effect on visibility.
-							pkgsettings.setcpv(pkg)
-							metadata["USE"] = pkgsettings["PORTAGE_USE"]
-							calculated_use = True
-						self._pkg_cache[pkg] = pkg
-
-					if not installed or (built and matched_packages):
-						# Only enforce visibility on installed packages
-						# if there is at least one other visible package
-						# available. By filtering installed masked packages
-						# here, packages that have been masked since they
-						# were installed can be automatically downgraded
-						# to an unmasked version.
-						try:
-							if not visible(pkgsettings, pkg):
-								continue
-						except portage.exception.InvalidDependString:
-							if not installed:
-								continue
-
-						# Enable upgrade or downgrade to a version
-						# with visible KEYWORDS when the installed
-						# version is masked by KEYWORDS, but never
-						# reinstall the same exact version only due
-						# to a KEYWORDS mask.
-						if built and matched_packages:
-
-							different_version = None
-							for avail_pkg in matched_packages:
-								if not portage.dep.cpvequal(
-									pkg.cpv, avail_pkg.cpv):
-									different_version = avail_pkg
-									break
-							if different_version is not None:
-
-								if installed and \
-									pkgsettings._getMissingKeywords(
-									pkg.cpv, pkg.metadata):
-									continue
-
-								# If the ebuild no longer exists or it's
-								# keywords have been dropped, reject built
-								# instances (installed or binary).
-								# If --usepkgonly is enabled, assume that
-								# the ebuild status should be ignored.
-								if not usepkgonly:
-									try:
-										pkg_eb = self._pkg(
-											pkg.cpv, "ebuild", root_config)
-									except portage.exception.PackageNotFound:
-										continue
-									else:
-										if not visible(pkgsettings, pkg_eb):
-											continue
-
-					if not pkg.built and not calculated_use:
-						# This is avoided whenever possible because
-						# it's expensive.
-						pkgsettings.setcpv(pkg)
-						pkg.metadata["USE"] = pkgsettings["PORTAGE_USE"]
-
-					if pkg.cp != atom.cp:
-						# A cpv can be returned from dbapi.match() as an
-						# old-style virtual match even in cases when the
-						# package does not actually PROVIDE the virtual.
-						# Filter out any such false matches here.
-						if not atom_set.findAtomForPackage(pkg):
-							continue
-
-					myarg = None
-					if root == self.target_root:
-						try:
-							# Ebuild USE must have been calculated prior
-							# to this point, in case atoms have USE deps.
-							myarg = self._iter_atoms_for_pkg(pkg).next()
-						except StopIteration:
-							pass
-						except portage.exception.InvalidDependString:
-							if not installed:
-								# masked by corruption
-								continue
-					if not installed and myarg:
-						found_available_arg = True
-
-					if atom.use and not pkg.built:
-						use = pkg.use.enabled
-						if atom.use.enabled.difference(use):
-							continue
-						if atom.use.disabled.intersection(use):
-							continue
-					if pkg.cp == atom_cp:
-						if highest_version is None:
-							highest_version = pkg
-						elif pkg > highest_version:
-							highest_version = pkg
-					# At this point, we've found the highest visible
-					# match from the current repo. Any lower versions
-					# from this repo are ignored, so this so the loop
-					# will always end with a break statement below
-					# this point.
-					if find_existing_node:
-						e_pkg = self._slot_pkg_map[root].get(pkg.slot_atom)
-						if not e_pkg:
-							break
-						if portage.dep.match_from_list(atom, [e_pkg]):
-							if highest_version and \
-								e_pkg.cp == atom_cp and \
-								e_pkg < highest_version and \
-								e_pkg.slot_atom != highest_version.slot_atom:
-								# There is a higher version available in a
-								# different slot, so this existing node is
-								# irrelevant.
-								pass
-							else:
-								matched_packages.append(e_pkg)
-								existing_node = e_pkg
-						break
-					# Compare built package to current config and
-					# reject the built package if necessary.
-					if built and not installed and \
-						("--newuse" in self.myopts or \
-						"--reinstall" in self.myopts):
-						iuses = pkg.iuse.all
-						old_use = pkg.use.enabled
-						if myeb:
-							pkgsettings.setcpv(myeb)
-						else:
-							pkgsettings.setcpv(pkg)
-						now_use = pkgsettings["PORTAGE_USE"].split()
-						forced_flags = set()
-						forced_flags.update(pkgsettings.useforce)
-						forced_flags.update(pkgsettings.usemask)
-						cur_iuse = iuses
-						if myeb and not usepkgonly:
-							cur_iuse = myeb.iuse.all
-						if self._reinstall_for_flags(forced_flags,
-							old_use, iuses,
-							now_use, cur_iuse):
-							break
-					# Compare current config to installed package
-					# and do not reinstall if possible.
-					if not installed and \
-						("--newuse" in self.myopts or \
-						"--reinstall" in self.myopts) and \
-						cpv in vardb.match(atom):
-						pkgsettings.setcpv(pkg)
-						forced_flags = set()
-						forced_flags.update(pkgsettings.useforce)
-						forced_flags.update(pkgsettings.usemask)
-						old_use = vardb.aux_get(cpv, ["USE"])[0].split()
-						old_iuse = set(filter_iuse_defaults(
-							vardb.aux_get(cpv, ["IUSE"])[0].split()))
-						cur_use = pkg.use.enabled
-						cur_iuse = pkg.iuse.all
-						reinstall_for_flags = \
-							self._reinstall_for_flags(
-							forced_flags, old_use, old_iuse,
-							cur_use, cur_iuse)
-						if reinstall_for_flags:
-							reinstall = True
-					if not built:
-						myeb = pkg
-					matched_packages.append(pkg)
-					if reinstall_for_flags:
-						self._reinstall_nodes[pkg] = \
-							reinstall_for_flags
-					break
-
-		if not matched_packages:
-			return None, None
-
-		if "--debug" in self.myopts:
-			for pkg in matched_packages:
-				portage.writemsg("%s %s\n" % \
-					((pkg.type_name + ":").rjust(10), pkg.cpv), noiselevel=-1)
-
-		# Filter out any old-style virtual matches if they are
-		# mixed with new-style virtual matches.
-		cp = portage.dep_getkey(atom)
-		if len(matched_packages) > 1 and \
-			"virtual" == portage.catsplit(cp)[0]:
-			for pkg in matched_packages:
-				if pkg.cp != cp:
-					continue
-				# Got a new-style virtual, so filter
-				# out any old-style virtuals.
-				matched_packages = [pkg for pkg in matched_packages \
-					if pkg.cp == cp]
-				break
-
-		if len(matched_packages) > 1:
-			bestmatch = portage.best(
-				[pkg.cpv for pkg in matched_packages])
-			matched_packages = [pkg for pkg in matched_packages \
-				if portage.dep.cpvequal(pkg.cpv, bestmatch)]
-
-		# ordered by type preference ("ebuild" type is the last resort)
-		return  matched_packages[-1], existing_node
-
-	def _select_pkg_from_graph(self, root, atom, onlydeps=False):
-		"""
-		Select packages that have already been added to the graph or
-		those that are installed and have not been scheduled for
-		replacement.
-		"""
-		graph_db = self._graph_trees[root]["porttree"].dbapi
-		matches = graph_db.match_pkgs(atom)
-		if not matches:
-			return None, None
-		pkg = matches[-1] # highest match
-		in_graph = self._slot_pkg_map[root].get(pkg.slot_atom)
-		return pkg, in_graph
-
-	def _complete_graph(self):
-		"""
-		Add any deep dependencies of required sets (args, system, world) that
-		have not been pulled into the graph yet. This ensures that the graph
-		is consistent such that initially satisfied deep dependencies are not
-		broken in the new graph. Initially unsatisfied dependencies are
-		irrelevant since we only want to avoid breaking dependencies that are
-		intially satisfied.
-
-		Since this method can consume enough time to disturb users, it is
-		currently only enabled by the --complete-graph option.
-		"""
-		if "--buildpkgonly" in self.myopts or \
-			"recurse" not in self.myparams:
-			return 1
-
-		if "complete" not in self.myparams:
-			# Skip this to avoid consuming enough time to disturb users.
-			return 1
-
-		# Put the depgraph into a mode that causes it to only
-		# select packages that have already been added to the
-		# graph or those that are installed and have not been
-		# scheduled for replacement. Also, toggle the "deep"
-		# parameter so that all dependencies are traversed and
-		# accounted for.
-		self._select_atoms = self._select_atoms_from_graph
-		self._select_package = self._select_pkg_from_graph
-		already_deep = "deep" in self.myparams
-		if not already_deep:
-			self.myparams.add("deep")
-
-		for root in self.roots:
-			required_set_names = self._required_set_names.copy()
-			if root == self.target_root and \
-				(already_deep or "empty" in self.myparams):
-				required_set_names.difference_update(self._sets)
-			if not required_set_names and not self._ignored_deps:
-				continue
-			root_config = self.roots[root]
-			setconfig = root_config.setconfig
-			args = []
-			# Reuse existing SetArg instances when available.
-			for arg in self.digraph.root_nodes():
-				if not isinstance(arg, SetArg):
-					continue
-				if arg.root_config != root_config:
-					continue
-				if arg.name in required_set_names:
-					args.append(arg)
-					required_set_names.remove(arg.name)
-			# Create new SetArg instances only when necessary.
-			for s in required_set_names:
-				expanded_set = InternalPackageSet(
-					initial_atoms=setconfig.getSetAtoms(s))
-				atom = SETPREFIX + s
-				args.append(SetArg(arg=atom, set=expanded_set,
-					root_config=root_config))
-			vardb = root_config.trees["vartree"].dbapi
-			for arg in args:
-				for atom in arg.set:
-					self._dep_stack.append(
-						Dependency(atom=atom, root=root, parent=arg))
-			if self._ignored_deps:
-				self._dep_stack.extend(self._ignored_deps)
-				self._ignored_deps = []
-			if not self._create_graph(allow_unsatisfied=True):
-				return 0
-			# Check the unsatisfied deps to see if any initially satisfied deps
-			# will become unsatisfied due to an upgrade. Initially unsatisfied
-			# deps are irrelevant since we only want to avoid breaking deps
-			# that are initially satisfied.
-			while self._unsatisfied_deps:
-				dep = self._unsatisfied_deps.pop()
-				matches = vardb.match_pkgs(dep.atom)
-				if not matches:
-					self._initially_unsatisfied_deps.append(dep)
-					continue
-				# An scheduled installation broke a deep dependency.
-				# Add the installed package to the graph so that it
-				# will be appropriately reported as a slot collision
-				# (possibly solvable via backtracking).
-				pkg = matches[-1] # highest match
-				if not self._add_pkg(pkg, dep):
-					return 0
-				if not self._create_graph(allow_unsatisfied=True):
-					return 0
-		return 1
-
-	def _pkg(self, cpv, type_name, root_config, installed=False):
-		"""
-		Get a package instance from the cache, or create a new
-		one if necessary. Raises KeyError from aux_get if it
-		failures for some reason (package does not exist or is
-		corrupt).
-		"""
-		operation = "merge"
-		if installed:
-			operation = "nomerge"
-		pkg = self._pkg_cache.get(
-			(type_name, root_config.root, cpv, operation))
-		if pkg is None:
-			tree_type = self.pkg_tree_map[type_name]
-			db = root_config.trees[tree_type].dbapi
-			db_keys = list(self._trees_orig[root_config.root][
-				tree_type].dbapi._aux_cache_keys)
-			try:
-				metadata = izip(db_keys, db.aux_get(cpv, db_keys))
-			except KeyError:
-				raise portage.exception.PackageNotFound(cpv)
-			pkg = Package(cpv=cpv, metadata=metadata,
-				root_config=root_config, installed=installed)
-			if type_name == "ebuild":
-				settings = self.pkgsettings[root_config.root]
-				settings.setcpv(pkg)
-				pkg.metadata["USE"] = settings["PORTAGE_USE"]
-				pkg.metadata['CHOST'] = settings.get('CHOST', '')
-			self._pkg_cache[pkg] = pkg
-		return pkg
-
-	def validate_blockers(self):
-		"""Remove any blockers from the digraph that do not match any of the
-		packages within the graph.  If necessary, create hard deps to ensure
-		correct merge order such that mutually blocking packages are never
-		installed simultaneously."""
-
-		if "--buildpkgonly" in self.myopts or \
-			"--nodeps" in self.myopts:
-			return True
-
-		#if "deep" in self.myparams:
-		if True:
-			# Pull in blockers from all installed packages that haven't already
-			# been pulled into the depgraph.  This is not enabled by default
-			# due to the performance penalty that is incurred by all the
-			# additional dep_check calls that are required.
-
-			dep_keys = ["DEPEND","RDEPEND","PDEPEND"]
-			for myroot in self.trees:
-				vardb = self.trees[myroot]["vartree"].dbapi
-				portdb = self.trees[myroot]["porttree"].dbapi
-				pkgsettings = self.pkgsettings[myroot]
-				final_db = self.mydbapi[myroot]
-
-				blocker_cache = BlockerCache(myroot, vardb)
-				stale_cache = set(blocker_cache)
-				for pkg in vardb:
-					cpv = pkg.cpv
-					stale_cache.discard(cpv)
-					pkg_in_graph = self.digraph.contains(pkg)
-
-					# Check for masked installed packages. Only warn about
-					# packages that are in the graph in order to avoid warning
-					# about those that will be automatically uninstalled during
-					# the merge process or by --depclean.
-					if pkg in final_db:
-						if pkg_in_graph and not visible(pkgsettings, pkg):
-							self._masked_installed.add(pkg)
-
-					blocker_atoms = None
-					blockers = None
-					if pkg_in_graph:
-						blockers = []
-						try:
-							blockers.extend(
-								self._blocker_parents.child_nodes(pkg))
-						except KeyError:
-							pass
-						try:
-							blockers.extend(
-								self._irrelevant_blockers.child_nodes(pkg))
-						except KeyError:
-							pass
-					if blockers is not None:
-						blockers = set(str(blocker.atom) \
-							for blocker in blockers)
-
-					# If this node has any blockers, create a "nomerge"
-					# node for it so that they can be enforced.
-					self.spinner.update()
-					blocker_data = blocker_cache.get(cpv)
-					if blocker_data is not None and \
-						blocker_data.counter != long(pkg.metadata["COUNTER"]):
-						blocker_data = None
-
-					# If blocker data from the graph is available, use
-					# it to validate the cache and update the cache if
-					# it seems invalid.
-					if blocker_data is not None and \
-						blockers is not None:
-						if not blockers.symmetric_difference(
-							blocker_data.atoms):
-							continue
-						blocker_data = None
-
-					if blocker_data is None and \
-						blockers is not None:
-						# Re-use the blockers from the graph.
-						blocker_atoms = sorted(blockers)
-						counter = long(pkg.metadata["COUNTER"])
-						blocker_data = \
-							blocker_cache.BlockerData(counter, blocker_atoms)
-						blocker_cache[pkg.cpv] = blocker_data
-						continue
-
-					if blocker_data:
-						blocker_atoms = blocker_data.atoms
-					else:
-						# Use aux_get() to trigger FakeVartree global
-						# updates on *DEPEND when appropriate.
-						depstr = " ".join(vardb.aux_get(pkg.cpv, dep_keys))
-						# It is crucial to pass in final_db here in order to
-						# optimize dep_check calls by eliminating atoms via
-						# dep_wordreduce and dep_eval calls.
-						try:
-							portage.dep._dep_check_strict = False
-							try:
-								success, atoms = portage.dep_check(depstr,
-									final_db, pkgsettings, myuse=pkg.use.enabled,
-									trees=self._graph_trees, myroot=myroot)
-							except Exception, e:
-								if isinstance(e, SystemExit):
-									raise
-								# This is helpful, for example, if a ValueError
-								# is thrown from cpv_expand due to multiple
-								# matches (this can happen if an atom lacks a
-								# category).
-								show_invalid_depstring_notice(
-									pkg, depstr, str(e))
-								del e
-								raise
-						finally:
-							portage.dep._dep_check_strict = True
-						if not success:
-							replacement_pkg = final_db.match_pkgs(pkg.slot_atom)
-							if replacement_pkg and \
-								replacement_pkg[0].operation == "merge":
-								# This package is being replaced anyway, so
-								# ignore invalid dependencies so as not to
-								# annoy the user too much (otherwise they'd be
-								# forced to manually unmerge it first).
-								continue
-							show_invalid_depstring_notice(pkg, depstr, atoms)
-							return False
-						blocker_atoms = [myatom for myatom in atoms \
-							if myatom.startswith("!")]
-						blocker_atoms.sort()
-						counter = long(pkg.metadata["COUNTER"])
-						blocker_cache[cpv] = \
-							blocker_cache.BlockerData(counter, blocker_atoms)
-					if blocker_atoms:
-						try:
-							for atom in blocker_atoms:
-								blocker = Blocker(atom=portage.dep.Atom(atom),
-									eapi=pkg.metadata["EAPI"], root=myroot)
-								self._blocker_parents.add(blocker, pkg)
-						except portage.exception.InvalidAtom, e:
-							depstr = " ".join(vardb.aux_get(pkg.cpv, dep_keys))
-							show_invalid_depstring_notice(
-								pkg, depstr, "Invalid Atom: %s" % (e,))
-							return False
-				for cpv in stale_cache:
-					del blocker_cache[cpv]
-				blocker_cache.flush()
-				del blocker_cache
-
-		# Discard any "uninstall" tasks scheduled by previous calls
-		# to this method, since those tasks may not make sense given
-		# the current graph state.
-		previous_uninstall_tasks = self._blocker_uninstalls.leaf_nodes()
-		if previous_uninstall_tasks:
-			self._blocker_uninstalls = digraph()
-			self.digraph.difference_update(previous_uninstall_tasks)
-
-		for blocker in self._blocker_parents.leaf_nodes():
-			self.spinner.update()
-			root_config = self.roots[blocker.root]
-			virtuals = root_config.settings.getvirtuals()
-			myroot = blocker.root
-			initial_db = self.trees[myroot]["vartree"].dbapi
-			final_db = self.mydbapi[myroot]
-			
-			provider_virtual = False
-			if blocker.cp in virtuals and \
-				not self._have_new_virt(blocker.root, blocker.cp):
-				provider_virtual = True
-
-			# Use this to check PROVIDE for each matched package
-			# when necessary.
-			atom_set = InternalPackageSet(
-				initial_atoms=[blocker.atom])
-
-			if provider_virtual:
-				atoms = []
-				for provider_entry in virtuals[blocker.cp]:
-					provider_cp = \
-						portage.dep_getkey(provider_entry)
-					atoms.append(blocker.atom.replace(
-						blocker.cp, provider_cp))
-			else:
-				atoms = [blocker.atom]
-
-			blocked_initial = set()
-			for atom in atoms:
-				for pkg in initial_db.match_pkgs(atom):
-					if atom_set.findAtomForPackage(pkg):
-						blocked_initial.add(pkg)
-
-			blocked_final = set()
-			for atom in atoms:
-				for pkg in final_db.match_pkgs(atom):
-					if atom_set.findAtomForPackage(pkg):
-						blocked_final.add(pkg)
-
-			if not blocked_initial and not blocked_final:
-				parent_pkgs = self._blocker_parents.parent_nodes(blocker)
-				self._blocker_parents.remove(blocker)
-				# Discard any parents that don't have any more blockers.
-				for pkg in parent_pkgs:
-					self._irrelevant_blockers.add(blocker, pkg)
-					if not self._blocker_parents.child_nodes(pkg):
-						self._blocker_parents.remove(pkg)
-				continue
-			for parent in self._blocker_parents.parent_nodes(blocker):
-				unresolved_blocks = False
-				depends_on_order = set()
-				for pkg in blocked_initial:
-					if pkg.slot_atom == parent.slot_atom:
-						# TODO: Support blocks within slots in cases where it
-						# might make sense.  For example, a new version might
-						# require that the old version be uninstalled at build
-						# time.
-						continue
-					if parent.installed:
-						# Two currently installed packages conflict with
-						# eachother. Ignore this case since the damage
-						# is already done and this would be likely to
-						# confuse users if displayed like a normal blocker.
-						continue
-
-					self._blocked_pkgs.add(pkg, blocker)
-
-					if parent.operation == "merge":
-						# Maybe the blocked package can be replaced or simply
-						# unmerged to resolve this block.
-						depends_on_order.add((pkg, parent))
-						continue
-					# None of the above blocker resolutions techniques apply,
-					# so apparently this one is unresolvable.
-					unresolved_blocks = True
-				for pkg in blocked_final:
-					if pkg.slot_atom == parent.slot_atom:
-						# TODO: Support blocks within slots.
-						continue
-					if parent.operation == "nomerge" and \
-						pkg.operation == "nomerge":
-						# This blocker will be handled the next time that a
-						# merge of either package is triggered.
-						continue
-
-					self._blocked_pkgs.add(pkg, blocker)
-
-					# Maybe the blocking package can be
-					# unmerged to resolve this block.
-					if parent.operation == "merge" and pkg.installed:
-						depends_on_order.add((pkg, parent))
-						continue
-					elif parent.operation == "nomerge":
-						depends_on_order.add((parent, pkg))
-						continue
-					# None of the above blocker resolutions techniques apply,
-					# so apparently this one is unresolvable.
-					unresolved_blocks = True
-
-				# Make sure we don't unmerge any package that have been pulled
-				# into the graph.
-				if not unresolved_blocks and depends_on_order:
-					for inst_pkg, inst_task in depends_on_order:
-						if self.digraph.contains(inst_pkg) and \
-							self.digraph.parent_nodes(inst_pkg):
-							unresolved_blocks = True
-							break
-
-				if not unresolved_blocks and depends_on_order:
-					for inst_pkg, inst_task in depends_on_order:
-						uninst_task = Package(built=inst_pkg.built,
-							cpv=inst_pkg.cpv, installed=inst_pkg.installed,
-							metadata=inst_pkg.metadata,
-							operation="uninstall",
-							root_config=inst_pkg.root_config,
-							type_name=inst_pkg.type_name)
-						self._pkg_cache[uninst_task] = uninst_task
-						# Enforce correct merge order with a hard dep.
-						self.digraph.addnode(uninst_task, inst_task,
-							priority=BlockerDepPriority.instance)
-						# Count references to this blocker so that it can be
-						# invalidated after nodes referencing it have been
-						# merged.
-						self._blocker_uninstalls.addnode(uninst_task, blocker)
-				if not unresolved_blocks and not depends_on_order:
-					self._irrelevant_blockers.add(blocker, parent)
-					self._blocker_parents.remove_edge(blocker, parent)
-					if not self._blocker_parents.parent_nodes(blocker):
-						self._blocker_parents.remove(blocker)
-					if not self._blocker_parents.child_nodes(parent):
-						self._blocker_parents.remove(parent)
-				if unresolved_blocks:
-					self._unsolvable_blockers.add(blocker, parent)
-
-		return True
-
-	def _accept_blocker_conflicts(self):
-		acceptable = False
-		for x in ("--buildpkgonly", "--fetchonly",
-			"--fetch-all-uri", "--nodeps"):
-			if x in self.myopts:
-				acceptable = True
-				break
-		return acceptable
-
-	def _merge_order_bias(self, mygraph):
-		"""
-		For optimal leaf node selection, promote deep system runtime deps and
-		order nodes from highest to lowest overall reference count.
-		"""
-
-		node_info = {}
-		for node in mygraph.order:
-			node_info[node] = len(mygraph.parent_nodes(node))
-		deep_system_deps = _find_deep_system_runtime_deps(mygraph)
-
-		def cmp_merge_preference(node1, node2):
-
-			if node1.operation == 'uninstall':
-				if node2.operation == 'uninstall':
-					return 0
-				return 1
-
-			if node2.operation == 'uninstall':
-				if node1.operation == 'uninstall':
-					return 0
-				return -1
-
-			node1_sys = node1 in deep_system_deps
-			node2_sys = node2 in deep_system_deps
-			if node1_sys != node2_sys:
-				if node1_sys:
-					return -1
-				return 1
-
-			return node_info[node2] - node_info[node1]
-
-		mygraph.order.sort(key=cmp_sort_key(cmp_merge_preference))
-
-	def altlist(self, reversed=False):
-
-		while self._serialized_tasks_cache is None:
-			self._resolve_conflicts()
-			try:
-				self._serialized_tasks_cache, self._scheduler_graph = \
-					self._serialize_tasks()
-			except self._serialize_tasks_retry:
-				pass
-
-		retlist = self._serialized_tasks_cache[:]
-		if reversed:
-			retlist.reverse()
-		return retlist
-
-	def schedulerGraph(self):
-		"""
-		The scheduler graph is identical to the normal one except that
-		uninstall edges are reversed in specific cases that require
-		conflicting packages to be temporarily installed simultaneously.
-		This is intended for use by the Scheduler in it's parallelization
-		logic. It ensures that temporary simultaneous installation of
-		conflicting packages is avoided when appropriate (especially for
-		!!atom blockers), but allowed in specific cases that require it.
-
-		Note that this method calls break_refs() which alters the state of
-		internal Package instances such that this depgraph instance should
-		not be used to perform any more calculations.
-		"""
-		if self._scheduler_graph is None:
-			self.altlist()
-		self.break_refs(self._scheduler_graph.order)
-		return self._scheduler_graph
-
-	def break_refs(self, nodes):
-		"""
-		Take a mergelist like that returned from self.altlist() and
-		break any references that lead back to the depgraph. This is
-		useful if you want to hold references to packages without
-		also holding the depgraph on the heap.
-		"""
-		for node in nodes:
-			if hasattr(node, "root_config"):
-				# The FakeVartree references the _package_cache which
-				# references the depgraph. So that Package instances don't
-				# hold the depgraph and FakeVartree on the heap, replace
-				# the RootConfig that references the FakeVartree with the
-				# original RootConfig instance which references the actual
-				# vartree.
-				node.root_config = \
-					self._trees_orig[node.root_config.root]["root_config"]
-
-	def _resolve_conflicts(self):
-		if not self._complete_graph():
-			raise self._unknown_internal_error()
-
-		if not self.validate_blockers():
-			raise self._unknown_internal_error()
-
-		if self._slot_collision_info:
-			self._process_slot_conflicts()
-
-	def _serialize_tasks(self):
-
-		if "--debug" in self.myopts:
-			writemsg("\ndigraph:\n\n", noiselevel=-1)
-			self.digraph.debug_print()
-			writemsg("\n", noiselevel=-1)
-
-		scheduler_graph = self.digraph.copy()
-
-		if '--nodeps' in self.myopts:
-			# Preserve the package order given on the command line.
-			return ([node for node in scheduler_graph \
-				if isinstance(node, Package) \
-				and node.operation == 'merge'], scheduler_graph)
-
-		mygraph=self.digraph.copy()
-		# Prune "nomerge" root nodes if nothing depends on them, since
-		# otherwise they slow down merge order calculation. Don't remove
-		# non-root nodes since they help optimize merge order in some cases
-		# such as revdep-rebuild.
-		removed_nodes = set()
-		while True:
-			for node in mygraph.root_nodes():
-				if not isinstance(node, Package) or \
-					node.installed or node.onlydeps:
-					removed_nodes.add(node)
-			if removed_nodes:
-				self.spinner.update()
-				mygraph.difference_update(removed_nodes)
-			if not removed_nodes:
-				break
-			removed_nodes.clear()
-		self._merge_order_bias(mygraph)
-		def cmp_circular_bias(n1, n2):
-			"""
-			RDEPEND is stronger than PDEPEND and this function
-			measures such a strength bias within a circular
-			dependency relationship.
-			"""
-			n1_n2_medium = n2 in mygraph.child_nodes(n1,
-				ignore_priority=priority_range.ignore_medium_soft)
-			n2_n1_medium = n1 in mygraph.child_nodes(n2,
-				ignore_priority=priority_range.ignore_medium_soft)
-			if n1_n2_medium == n2_n1_medium:
-				return 0
-			elif n1_n2_medium:
-				return 1
-			return -1
-		myblocker_uninstalls = self._blocker_uninstalls.copy()
-		retlist=[]
-		# Contains uninstall tasks that have been scheduled to
-		# occur after overlapping blockers have been installed.
-		scheduled_uninstalls = set()
-		# Contains any Uninstall tasks that have been ignored
-		# in order to avoid the circular deps code path. These
-		# correspond to blocker conflicts that could not be
-		# resolved.
-		ignored_uninstall_tasks = set()
-		have_uninstall_task = False
-		complete = "complete" in self.myparams
-		asap_nodes = []
-
-		def get_nodes(**kwargs):
-			"""
-			Returns leaf nodes excluding Uninstall instances
-			since those should be executed as late as possible.
-			"""
-			return [node for node in mygraph.leaf_nodes(**kwargs) \
-				if isinstance(node, Package) and \
-					(node.operation != "uninstall" or \
-					node in scheduled_uninstalls)]
-
-		# sys-apps/portage needs special treatment if ROOT="/"
-		running_root = self._running_root.root
-		from portage.const import PORTAGE_PACKAGE_ATOM
-		runtime_deps = InternalPackageSet(
-			initial_atoms=[PORTAGE_PACKAGE_ATOM])
-		running_portage = self.trees[running_root]["vartree"].dbapi.match_pkgs(
-			PORTAGE_PACKAGE_ATOM)
-		replacement_portage = self.mydbapi[running_root].match_pkgs(
-			PORTAGE_PACKAGE_ATOM)
-
-		if running_portage:
-			running_portage = running_portage[0]
-		else:
-			running_portage = None
-
-		if replacement_portage:
-			replacement_portage = replacement_portage[0]
-		else:
-			replacement_portage = None
-
-		if replacement_portage == running_portage:
-			replacement_portage = None
-
-		if replacement_portage is not None:
-			# update from running_portage to replacement_portage asap
-			asap_nodes.append(replacement_portage)
-
-		if running_portage is not None:
-			try:
-				portage_rdepend = self._select_atoms_highest_available(
-					running_root, running_portage.metadata["RDEPEND"],
-					myuse=running_portage.use.enabled,
-					parent=running_portage, strict=False)
-			except portage.exception.InvalidDependString, e:
-				portage.writemsg("!!! Invalid RDEPEND in " + \
-					"'%svar/db/pkg/%s/RDEPEND': %s\n" % \
-					(running_root, running_portage.cpv, e), noiselevel=-1)
-				del e
-				portage_rdepend = []
-			runtime_deps.update(atom for atom in portage_rdepend \
-				if not atom.startswith("!"))
-
-		def gather_deps(ignore_priority, mergeable_nodes,
-			selected_nodes, node):
-			"""
-			Recursively gather a group of nodes that RDEPEND on
-			eachother. This ensures that they are merged as a group
-			and get their RDEPENDs satisfied as soon as possible.
-			"""
-			if node in selected_nodes:
-				return True
-			if node not in mergeable_nodes:
-				return False
-			if node == replacement_portage and \
-				mygraph.child_nodes(node,
-				ignore_priority=priority_range.ignore_medium_soft):
-				# Make sure that portage always has all of it's
-				# RDEPENDs installed first.
-				return False
-			selected_nodes.add(node)
-			for child in mygraph.child_nodes(node,
-				ignore_priority=ignore_priority):
-				if not gather_deps(ignore_priority,
-					mergeable_nodes, selected_nodes, child):
-					return False
-			return True
-
-		def ignore_uninst_or_med(priority):
-			if priority is BlockerDepPriority.instance:
-				return True
-			return priority_range.ignore_medium(priority)
-
-		def ignore_uninst_or_med_soft(priority):
-			if priority is BlockerDepPriority.instance:
-				return True
-			return priority_range.ignore_medium_soft(priority)
-
-		tree_mode = "--tree" in self.myopts
-		# Tracks whether or not the current iteration should prefer asap_nodes
-		# if available.  This is set to False when the previous iteration
-		# failed to select any nodes.  It is reset whenever nodes are
-		# successfully selected.
-		prefer_asap = True
-
-		# Controls whether or not the current iteration should drop edges that
-		# are "satisfied" by installed packages, in order to solve circular
-		# dependencies. The deep runtime dependencies of installed packages are
-		# not checked in this case (bug #199856), so it must be avoided
-		# whenever possible.
-		drop_satisfied = False
-
-		# State of variables for successive iterations that loosen the
-		# criteria for node selection.
-		#
-		# iteration   prefer_asap   drop_satisfied
-		# 1           True          False
-		# 2           False         False
-		# 3           False         True
-		#
-		# If no nodes are selected on the last iteration, it is due to
-		# unresolved blockers or circular dependencies.
-
-		while not mygraph.empty():
-			self.spinner.update()
-			selected_nodes = None
-			ignore_priority = None
-			if drop_satisfied or (prefer_asap and asap_nodes):
-				priority_range = DepPrioritySatisfiedRange
-			else:
-				priority_range = DepPriorityNormalRange
-			if prefer_asap and asap_nodes:
-				# ASAP nodes are merged before their soft deps. Go ahead and
-				# select root nodes here if necessary, since it's typical for
-				# the parent to have been removed from the graph already.
-				asap_nodes = [node for node in asap_nodes \
-					if mygraph.contains(node)]
-				for node in asap_nodes:
-					if not mygraph.child_nodes(node,
-						ignore_priority=priority_range.ignore_soft):
-						selected_nodes = [node]
-						asap_nodes.remove(node)
-						break
-			if not selected_nodes and \
-				not (prefer_asap and asap_nodes):
-				for i in xrange(priority_range.NONE,
-					priority_range.MEDIUM_SOFT + 1):
-					ignore_priority = priority_range.ignore_priority[i]
-					nodes = get_nodes(ignore_priority=ignore_priority)
-					if nodes:
-						# If there is a mix of uninstall nodes with other
-						# types, save the uninstall nodes for later since
-						# sometimes a merge node will render an uninstall
-						# node unnecessary (due to occupying the same slot),
-						# and we want to avoid executing a separate uninstall
-						# task in that case.
-						if len(nodes) > 1:
-							good_uninstalls = []
-							with_some_uninstalls_excluded = []
-							for node in nodes:
-								if node.operation == "uninstall":
-									slot_node = self.mydbapi[node.root
-										].match_pkgs(node.slot_atom)
-									if slot_node and \
-										slot_node[0].operation == "merge":
-										continue
-									good_uninstalls.append(node)
-								with_some_uninstalls_excluded.append(node)
-							if good_uninstalls:
-								nodes = good_uninstalls
-							elif with_some_uninstalls_excluded:
-								nodes = with_some_uninstalls_excluded
-							else:
-								nodes = nodes
-
-						if ignore_priority is None and not tree_mode:
-							# Greedily pop all of these nodes since no
-							# relationship has been ignored. This optimization
-							# destroys --tree output, so it's disabled in tree
-							# mode.
-							selected_nodes = nodes
-						else:
-							# For optimal merge order:
-							#  * Only pop one node.
-							#  * Removing a root node (node without a parent)
-							#    will not produce a leaf node, so avoid it.
-							#  * It's normal for a selected uninstall to be a
-							#    root node, so don't check them for parents.
-							for node in nodes:
-								if node.operation == "uninstall" or \
-									mygraph.parent_nodes(node):
-									selected_nodes = [node]
-									break
-
-						if selected_nodes:
-							break
-
-			if not selected_nodes:
-				nodes = get_nodes(ignore_priority=priority_range.ignore_medium)
-				if nodes:
-					mergeable_nodes = set(nodes)
-					if prefer_asap and asap_nodes:
-						nodes = asap_nodes
-					for i in xrange(priority_range.SOFT,
-						priority_range.MEDIUM_SOFT + 1):
-						ignore_priority = priority_range.ignore_priority[i]
-						for node in nodes:
-							if not mygraph.parent_nodes(node):
-								continue
-							selected_nodes = set()
-							if gather_deps(ignore_priority,
-								mergeable_nodes, selected_nodes, node):
-								break
-							else:
-								selected_nodes = None
-						if selected_nodes:
-							break
-
-					if prefer_asap and asap_nodes and not selected_nodes:
-						# We failed to find any asap nodes to merge, so ignore
-						# them for the next iteration.
-						prefer_asap = False
-						continue
-
-			if selected_nodes and ignore_priority is not None:
-				# Try to merge ignored medium_soft deps as soon as possible
-				# if they're not satisfied by installed packages.
-				for node in selected_nodes:
-					children = set(mygraph.child_nodes(node))
-					soft = children.difference(
-						mygraph.child_nodes(node,
-						ignore_priority=DepPrioritySatisfiedRange.ignore_soft))
-					medium_soft = children.difference(
-						mygraph.child_nodes(node,
-							ignore_priority = \
-							DepPrioritySatisfiedRange.ignore_medium_soft))
-					medium_soft.difference_update(soft)
-					for child in medium_soft:
-						if child in selected_nodes:
-							continue
-						if child in asap_nodes:
-							continue
-						asap_nodes.append(child)
-
-			if selected_nodes and len(selected_nodes) > 1:
-				if not isinstance(selected_nodes, list):
-					selected_nodes = list(selected_nodes)
-				selected_nodes.sort(key=cmp_sort_key(cmp_circular_bias))
-
-			if not selected_nodes and not myblocker_uninstalls.is_empty():
-				# An Uninstall task needs to be executed in order to
-				# avoid conflict if possible.
-
-				if drop_satisfied:
-					priority_range = DepPrioritySatisfiedRange
-				else:
-					priority_range = DepPriorityNormalRange
-
-				mergeable_nodes = get_nodes(
-					ignore_priority=ignore_uninst_or_med)
-
-				min_parent_deps = None
-				uninst_task = None
-				for task in myblocker_uninstalls.leaf_nodes():
-					# Do some sanity checks so that system or world packages
-					# don't get uninstalled inappropriately here (only really
-					# necessary when --complete-graph has not been enabled).
-
-					if task in ignored_uninstall_tasks:
-						continue
-
-					if task in scheduled_uninstalls:
-						# It's been scheduled but it hasn't
-						# been executed yet due to dependence
-						# on installation of blocking packages.
-						continue
-
-					root_config = self.roots[task.root]
-					inst_pkg = self._pkg_cache[
-						("installed", task.root, task.cpv, "nomerge")]
-
-					if self.digraph.contains(inst_pkg):
-						continue
-
-					forbid_overlap = False
-					heuristic_overlap = False
-					for blocker in myblocker_uninstalls.parent_nodes(task):
-						if blocker.eapi in ("0", "1"):
-							heuristic_overlap = True
-						elif blocker.atom.blocker.overlap.forbid:
-							forbid_overlap = True
-							break
-					if forbid_overlap and running_root == task.root:
-						continue
-
-					if heuristic_overlap and running_root == task.root:
-						# Never uninstall sys-apps/portage or it's essential
-						# dependencies, except through replacement.
-						try:
-							runtime_dep_atoms = \
-								list(runtime_deps.iterAtomsForPackage(task))
-						except portage.exception.InvalidDependString, e:
-							portage.writemsg("!!! Invalid PROVIDE in " + \
-								"'%svar/db/pkg/%s/PROVIDE': %s\n" % \
-								(task.root, task.cpv, e), noiselevel=-1)
-							del e
-							continue
-
-						# Don't uninstall a runtime dep if it appears
-						# to be the only suitable one installed.
-						skip = False
-						vardb = root_config.trees["vartree"].dbapi
-						for atom in runtime_dep_atoms:
-							other_version = None
-							for pkg in vardb.match_pkgs(atom):
-								if pkg.cpv == task.cpv and \
-									pkg.metadata["COUNTER"] == \
-									task.metadata["COUNTER"]:
-									continue
-								other_version = pkg
-								break
-							if other_version is None:
-								skip = True
-								break
-						if skip:
-							continue
-
-						# For packages in the system set, don't take
-						# any chances. If the conflict can't be resolved
-						# by a normal replacement operation then abort.
-						skip = False
-						try:
-							for atom in root_config.sets[
-								"system"].iterAtomsForPackage(task):
-								skip = True
-								break
-						except portage.exception.InvalidDependString, e:
-							portage.writemsg("!!! Invalid PROVIDE in " + \
-								"'%svar/db/pkg/%s/PROVIDE': %s\n" % \
-								(task.root, task.cpv, e), noiselevel=-1)
-							del e
-							skip = True
-						if skip:
-							continue
-
-					# Note that the world check isn't always
-					# necessary since self._complete_graph() will
-					# add all packages from the system and world sets to the
-					# graph. This just allows unresolved conflicts to be
-					# detected as early as possible, which makes it possible
-					# to avoid calling self._complete_graph() when it is
-					# unnecessary due to blockers triggering an abortion.
-					if not complete:
-						# For packages in the world set, go ahead an uninstall
-						# when necessary, as long as the atom will be satisfied
-						# in the final state.
-						graph_db = self.mydbapi[task.root]
-						skip = False
-						try:
-							for atom in root_config.sets[
-								"world"].iterAtomsForPackage(task):
-								satisfied = False
-								for pkg in graph_db.match_pkgs(atom):
-									if pkg == inst_pkg:
-										continue
-									satisfied = True
-									break
-								if not satisfied:
-									skip = True
-									self._blocked_world_pkgs[inst_pkg] = atom
-									break
-						except portage.exception.InvalidDependString, e:
-							portage.writemsg("!!! Invalid PROVIDE in " + \
-								"'%svar/db/pkg/%s/PROVIDE': %s\n" % \
-								(task.root, task.cpv, e), noiselevel=-1)
-							del e
-							skip = True
-						if skip:
-							continue
-
-					# Check the deps of parent nodes to ensure that
-					# the chosen task produces a leaf node. Maybe
-					# this can be optimized some more to make the
-					# best possible choice, but the current algorithm
-					# is simple and should be near optimal for most
-					# common cases.
-					mergeable_parent = False
-					parent_deps = set()
-					for parent in mygraph.parent_nodes(task):
-						parent_deps.update(mygraph.child_nodes(parent,
-							ignore_priority=priority_range.ignore_medium_soft))
-						if parent in mergeable_nodes and \
-							gather_deps(ignore_uninst_or_med_soft,
-							mergeable_nodes, set(), parent):
-							mergeable_parent = True
-
-					if not mergeable_parent:
-						continue
-
-					parent_deps.remove(task)
-					if min_parent_deps is None or \
-						len(parent_deps) < min_parent_deps:
-						min_parent_deps = len(parent_deps)
-						uninst_task = task
-
-				if uninst_task is not None:
-					# The uninstall is performed only after blocking
-					# packages have been merged on top of it. File
-					# collisions between blocking packages are detected
-					# and removed from the list of files to be uninstalled.
-					scheduled_uninstalls.add(uninst_task)
-					parent_nodes = mygraph.parent_nodes(uninst_task)
-
-					# Reverse the parent -> uninstall edges since we want
-					# to do the uninstall after blocking packages have
-					# been merged on top of it.
-					mygraph.remove(uninst_task)
-					for blocked_pkg in parent_nodes:
-						mygraph.add(blocked_pkg, uninst_task,
-							priority=BlockerDepPriority.instance)
-						scheduler_graph.remove_edge(uninst_task, blocked_pkg)
-						scheduler_graph.add(blocked_pkg, uninst_task,
-							priority=BlockerDepPriority.instance)
-
-					# Reset the state variables for leaf node selection and
-					# continue trying to select leaf nodes.
-					prefer_asap = True
-					drop_satisfied = False
-					continue
-
-			if not selected_nodes:
-				# Only select root nodes as a last resort. This case should
-				# only trigger when the graph is nearly empty and the only
-				# remaining nodes are isolated (no parents or children). Since
-				# the nodes must be isolated, ignore_priority is not needed.
-				selected_nodes = get_nodes()
-
-			if not selected_nodes and not drop_satisfied:
-				drop_satisfied = True
-				continue
-
-			if not selected_nodes and not myblocker_uninstalls.is_empty():
-				# If possible, drop an uninstall task here in order to avoid
-				# the circular deps code path. The corresponding blocker will
-				# still be counted as an unresolved conflict.
-				uninst_task = None
-				for node in myblocker_uninstalls.leaf_nodes():
-					try:
-						mygraph.remove(node)
-					except KeyError:
-						pass
-					else:
-						uninst_task = node
-						ignored_uninstall_tasks.add(node)
-						break
-
-				if uninst_task is not None:
-					# Reset the state variables for leaf node selection and
-					# continue trying to select leaf nodes.
-					prefer_asap = True
-					drop_satisfied = False
-					continue
-
-			if not selected_nodes:
-				self._circular_deps_for_display = mygraph
-				raise self._unknown_internal_error()
-
-			# At this point, we've succeeded in selecting one or more nodes, so
-			# reset state variables for leaf node selection.
-			prefer_asap = True
-			drop_satisfied = False
-
-			mygraph.difference_update(selected_nodes)
-
-			for node in selected_nodes:
-				if isinstance(node, Package) and \
-					node.operation == "nomerge":
-					continue
-
-				# Handle interactions between blockers
-				# and uninstallation tasks.
-				solved_blockers = set()
-				uninst_task = None
-				if isinstance(node, Package) and \
-					"uninstall" == node.operation:
-					have_uninstall_task = True
-					uninst_task = node
-				else:
-					vardb = self.trees[node.root]["vartree"].dbapi
-					previous_cpv = vardb.match(node.slot_atom)
-					if previous_cpv:
-						# The package will be replaced by this one, so remove
-						# the corresponding Uninstall task if necessary.
-						previous_cpv = previous_cpv[0]
-						uninst_task = \
-							("installed", node.root, previous_cpv, "uninstall")
-						try:
-							mygraph.remove(uninst_task)
-						except KeyError:
-							pass
-
-				if uninst_task is not None and \
-					uninst_task not in ignored_uninstall_tasks and \
-					myblocker_uninstalls.contains(uninst_task):
-					blocker_nodes = myblocker_uninstalls.parent_nodes(uninst_task)
-					myblocker_uninstalls.remove(uninst_task)
-					# Discard any blockers that this Uninstall solves.
-					for blocker in blocker_nodes:
-						if not myblocker_uninstalls.child_nodes(blocker):
-							myblocker_uninstalls.remove(blocker)
-							solved_blockers.add(blocker)
-
-				retlist.append(node)
-
-				if (isinstance(node, Package) and \
-					"uninstall" == node.operation) or \
-					(uninst_task is not None and \
-					uninst_task in scheduled_uninstalls):
-					# Include satisfied blockers in the merge list
-					# since the user might be interested and also
-					# it serves as an indicator that blocking packages
-					# will be temporarily installed simultaneously.
-					for blocker in solved_blockers:
-						retlist.append(Blocker(atom=blocker.atom,
-							root=blocker.root, eapi=blocker.eapi,
-							satisfied=True))
-
-		unsolvable_blockers = set(self._unsolvable_blockers.leaf_nodes())
-		for node in myblocker_uninstalls.root_nodes():
-			unsolvable_blockers.add(node)
-
-		for blocker in unsolvable_blockers:
-			retlist.append(blocker)
-
-		# If any Uninstall tasks need to be executed in order
-		# to avoid a conflict, complete the graph with any
-		# dependencies that may have been initially
-		# neglected (to ensure that unsafe Uninstall tasks
-		# are properly identified and blocked from execution).
-		if have_uninstall_task and \
-			not complete and \
-			not unsolvable_blockers:
-			self.myparams.add("complete")
-			raise self._serialize_tasks_retry("")
-
-		if unsolvable_blockers and \
-			not self._accept_blocker_conflicts():
-			self._unsatisfied_blockers_for_display = unsolvable_blockers
-			self._serialized_tasks_cache = retlist[:]
-			self._scheduler_graph = scheduler_graph
-			raise self._unknown_internal_error()
-
-		if self._slot_collision_info and \
-			not self._accept_blocker_conflicts():
-			self._serialized_tasks_cache = retlist[:]
-			self._scheduler_graph = scheduler_graph
-			raise self._unknown_internal_error()
-
-		return retlist, scheduler_graph
-
-	def _show_circular_deps(self, mygraph):
-		# No leaf nodes are available, so we have a circular
-		# dependency panic situation.  Reduce the noise level to a
-		# minimum via repeated elimination of root nodes since they
-		# have no parents and thus can not be part of a cycle.
-		while True:
-			root_nodes = mygraph.root_nodes(
-				ignore_priority=DepPrioritySatisfiedRange.ignore_medium_soft)
-			if not root_nodes:
-				break
-			mygraph.difference_update(root_nodes)
-		# Display the USE flags that are enabled on nodes that are part
-		# of dependency cycles in case that helps the user decide to
-		# disable some of them.
-		display_order = []
-		tempgraph = mygraph.copy()
-		while not tempgraph.empty():
-			nodes = tempgraph.leaf_nodes()
-			if not nodes:
-				node = tempgraph.order[0]
-			else:
-				node = nodes[0]
-			display_order.append(node)
-			tempgraph.remove(node)
-		display_order.reverse()
-		self.myopts.pop("--quiet", None)
-		self.myopts.pop("--verbose", None)
-		self.myopts["--tree"] = True
-		portage.writemsg("\n\n", noiselevel=-1)
-		self.display(display_order)
-		prefix = colorize("BAD", " * ")
-		portage.writemsg("\n", noiselevel=-1)
-		portage.writemsg(prefix + "Error: circular dependencies:\n",
-			noiselevel=-1)
-		portage.writemsg("\n", noiselevel=-1)
-		mygraph.debug_print()
-		portage.writemsg("\n", noiselevel=-1)
-		portage.writemsg(prefix + "Note that circular dependencies " + \
-			"can often be avoided by temporarily\n", noiselevel=-1)
-		portage.writemsg(prefix + "disabling USE flags that trigger " + \
-			"optional dependencies.\n", noiselevel=-1)
-
-	def _show_merge_list(self):
-		if self._serialized_tasks_cache is not None and \
-			not (self._displayed_list and \
-			(self._displayed_list == self._serialized_tasks_cache or \
-			self._displayed_list == \
-				list(reversed(self._serialized_tasks_cache)))):
-			display_list = self._serialized_tasks_cache[:]
-			if "--tree" in self.myopts:
-				display_list.reverse()
-			self.display(display_list)
-
-	def _show_unsatisfied_blockers(self, blockers):
-		self._show_merge_list()
-		msg = "Error: The above package list contains " + \
-			"packages which cannot be installed " + \
-			"at the same time on the same system."
-		prefix = colorize("BAD", " * ")
-		from textwrap import wrap
-		portage.writemsg("\n", noiselevel=-1)
-		for line in wrap(msg, 70):
-			portage.writemsg(prefix + line + "\n", noiselevel=-1)
-
-		# Display the conflicting packages along with the packages
-		# that pulled them in. This is helpful for troubleshooting
-		# cases in which blockers don't solve automatically and
-		# the reasons are not apparent from the normal merge list
-		# display.
-
-		conflict_pkgs = {}
-		for blocker in blockers:
-			for pkg in chain(self._blocked_pkgs.child_nodes(blocker), \
-				self._blocker_parents.parent_nodes(blocker)):
-				parent_atoms = self._parent_atoms.get(pkg)
-				if not parent_atoms:
-					atom = self._blocked_world_pkgs.get(pkg)
-					if atom is not None:
-						parent_atoms = set([("@world", atom)])
-				if parent_atoms:
-					conflict_pkgs[pkg] = parent_atoms
-
-		if conflict_pkgs:
-			# Reduce noise by pruning packages that are only
-			# pulled in by other conflict packages.
-			pruned_pkgs = set()
-			for pkg, parent_atoms in conflict_pkgs.iteritems():
-				relevant_parent = False
-				for parent, atom in parent_atoms:
-					if parent not in conflict_pkgs:
-						relevant_parent = True
-						break
-				if not relevant_parent:
-					pruned_pkgs.add(pkg)
-			for pkg in pruned_pkgs:
-				del conflict_pkgs[pkg]
-
-		if conflict_pkgs:
-			msg = []
-			msg.append("\n")
-			indent = "  "
-			# Max number of parents shown, to avoid flooding the display.
-			max_parents = 3
-			for pkg, parent_atoms in conflict_pkgs.iteritems():
-
-				pruned_list = set()
-
-				# Prefer packages that are not directly involved in a conflict.
-				for parent_atom in parent_atoms:
-					if len(pruned_list) >= max_parents:
-						break
-					parent, atom = parent_atom
-					if parent not in conflict_pkgs:
-						pruned_list.add(parent_atom)
-
-				for parent_atom in parent_atoms:
-					if len(pruned_list) >= max_parents:
-						break
-					pruned_list.add(parent_atom)
-
-				omitted_parents = len(parent_atoms) - len(pruned_list)
-				msg.append(indent + "%s pulled in by\n" % pkg)
-
-				for parent_atom in pruned_list:
-					parent, atom = parent_atom
-					msg.append(2*indent)
-					if isinstance(parent,
-						(PackageArg, AtomArg)):
-						# For PackageArg and AtomArg types, it's
-						# redundant to display the atom attribute.
-						msg.append(str(parent))
-					else:
-						# Display the specific atom from SetArg or
-						# Package types.
-						msg.append("%s required by %s" % (atom, parent))
-					msg.append("\n")
-
-				if omitted_parents:
-					msg.append(2*indent)
-					msg.append("(and %d more)\n" % omitted_parents)
-
-				msg.append("\n")
-
-			sys.stderr.write("".join(msg))
-			sys.stderr.flush()
-
-		if "--quiet" not in self.myopts:
-			show_blocker_docs_link()
-
-	def display(self, mylist, favorites=[], verbosity=None):
-
-		# This is used to prevent display_problems() from
-		# redundantly displaying this exact same merge list
-		# again via _show_merge_list().
-		self._displayed_list = mylist
-
-		if verbosity is None:
-			verbosity = ("--quiet" in self.myopts and 1 or \
-				"--verbose" in self.myopts and 3 or 2)
-		favorites_set = InternalPackageSet(favorites)
-		oneshot = "--oneshot" in self.myopts or \
-			"--onlydeps" in self.myopts
-		columns = "--columns" in self.myopts
-		changelogs=[]
-		p=[]
-		blockers = []
-
-		counters = PackageCounters()
-
-		if verbosity == 1 and "--verbose" not in self.myopts:
-			def create_use_string(*args):
-				return ""
-		else:
-			def create_use_string(name, cur_iuse, iuse_forced, cur_use,
-				old_iuse, old_use,
-				is_new, reinst_flags,
-				all_flags=(verbosity == 3 or "--quiet" in self.myopts),
-				alphabetical=("--alphabetical" in self.myopts)):
-				enabled = []
-				if alphabetical:
-					disabled = enabled
-					removed = enabled
-				else:
-					disabled = []
-					removed = []
-				cur_iuse = set(cur_iuse)
-				enabled_flags = cur_iuse.intersection(cur_use)
-				removed_iuse = set(old_iuse).difference(cur_iuse)
-				any_iuse = cur_iuse.union(old_iuse)
-				any_iuse = list(any_iuse)
-				any_iuse.sort()
-				for flag in any_iuse:
-					flag_str = None
-					isEnabled = False
-					reinst_flag = reinst_flags and flag in reinst_flags
-					if flag in enabled_flags:
-						isEnabled = True
-						if is_new or flag in old_use and \
-							(all_flags or reinst_flag):
-							flag_str = red(flag)
-						elif flag not in old_iuse:
-							flag_str = yellow(flag) + "%*"
-						elif flag not in old_use:
-							flag_str = green(flag) + "*"
-					elif flag in removed_iuse:
-						if all_flags or reinst_flag:
-							flag_str = yellow("-" + flag) + "%"
-							if flag in old_use:
-								flag_str += "*"
-							flag_str = "(" + flag_str + ")"
-							removed.append(flag_str)
-						continue
-					else:
-						if is_new or flag in old_iuse and \
-							flag not in old_use and \
-							(all_flags or reinst_flag):
-							flag_str = blue("-" + flag)
-						elif flag not in old_iuse:
-							flag_str = yellow("-" + flag)
-							if flag not in iuse_forced:
-								flag_str += "%"
-						elif flag in old_use:
-							flag_str = green("-" + flag) + "*"
-					if flag_str:
-						if flag in iuse_forced:
-							flag_str = "(" + flag_str + ")"
-						if isEnabled:
-							enabled.append(flag_str)
-						else:
-							disabled.append(flag_str)
-
-				if alphabetical:
-					ret = " ".join(enabled)
-				else:
-					ret = " ".join(enabled + disabled + removed)
-				if ret:
-					ret = '%s="%s" ' % (name, ret)
-				return ret
-
-		repo_display = RepoDisplay(self.roots)
-
-		tree_nodes = []
-		display_list = []
-		mygraph = self.digraph.copy()
-
-		# If there are any Uninstall instances, add the corresponding
-		# blockers to the digraph (useful for --tree display).
-
-		executed_uninstalls = set(node for node in mylist \
-			if isinstance(node, Package) and node.operation == "unmerge")
-
-		for uninstall in self._blocker_uninstalls.leaf_nodes():
-			uninstall_parents = \
-				self._blocker_uninstalls.parent_nodes(uninstall)
-			if not uninstall_parents:
-				continue
-
-			# Remove the corresponding "nomerge" node and substitute
-			# the Uninstall node.
-			inst_pkg = self._pkg_cache[
-				("installed", uninstall.root, uninstall.cpv, "nomerge")]
-			try:
-				mygraph.remove(inst_pkg)
-			except KeyError:
-				pass
-
-			try:
-				inst_pkg_blockers = self._blocker_parents.child_nodes(inst_pkg)
-			except KeyError:
-				inst_pkg_blockers = []
-
-			# Break the Package -> Uninstall edges.
-			mygraph.remove(uninstall)
-
-			# Resolution of a package's blockers
-			# depend on it's own uninstallation.
-			for blocker in inst_pkg_blockers:
-				mygraph.add(uninstall, blocker)
-
-			# Expand Package -> Uninstall edges into
-			# Package -> Blocker -> Uninstall edges.
-			for blocker in uninstall_parents:
-				mygraph.add(uninstall, blocker)
-				for parent in self._blocker_parents.parent_nodes(blocker):
-					if parent != inst_pkg:
-						mygraph.add(blocker, parent)
-
-			# If the uninstall task did not need to be executed because
-			# of an upgrade, display Blocker -> Upgrade edges since the
-			# corresponding Blocker -> Uninstall edges will not be shown.
-			upgrade_node = \
-				self._slot_pkg_map[uninstall.root].get(uninstall.slot_atom)
-			if upgrade_node is not None and \
-				uninstall not in executed_uninstalls:
-				for blocker in uninstall_parents:
-					mygraph.add(upgrade_node, blocker)
-
-		unsatisfied_blockers = []
-		i = 0
-		depth = 0
-		shown_edges = set()
-		for x in mylist:
-			if isinstance(x, Blocker) and not x.satisfied:
-				unsatisfied_blockers.append(x)
-				continue
-			graph_key = x
-			if "--tree" in self.myopts:
-				depth = len(tree_nodes)
-				while depth and graph_key not in \
-					mygraph.child_nodes(tree_nodes[depth-1]):
-						depth -= 1
-				if depth:
-					tree_nodes = tree_nodes[:depth]
-					tree_nodes.append(graph_key)
-					display_list.append((x, depth, True))
-					shown_edges.add((graph_key, tree_nodes[depth-1]))
-				else:
-					traversed_nodes = set() # prevent endless circles
-					traversed_nodes.add(graph_key)
-					def add_parents(current_node, ordered):
-						parent_nodes = None
-						# Do not traverse to parents if this node is an
-						# an argument or a direct member of a set that has
-						# been specified as an argument (system or world).
-						if current_node not in self._set_nodes:
-							parent_nodes = mygraph.parent_nodes(current_node)
-						if parent_nodes:
-							child_nodes = set(mygraph.child_nodes(current_node))
-							selected_parent = None
-							# First, try to avoid a direct cycle.
-							for node in parent_nodes:
-								if not isinstance(node, (Blocker, Package)):
-									continue
-								if node not in traversed_nodes and \
-									node not in child_nodes:
-									edge = (current_node, node)
-									if edge in shown_edges:
-										continue
-									selected_parent = node
-									break
-							if not selected_parent:
-								# A direct cycle is unavoidable.
-								for node in parent_nodes:
-									if not isinstance(node, (Blocker, Package)):
-										continue
-									if node not in traversed_nodes:
-										edge = (current_node, node)
-										if edge in shown_edges:
-											continue
-										selected_parent = node
-										break
-							if selected_parent:
-								shown_edges.add((current_node, selected_parent))
-								traversed_nodes.add(selected_parent)
-								add_parents(selected_parent, False)
-						display_list.append((current_node,
-							len(tree_nodes), ordered))
-						tree_nodes.append(current_node)
-					tree_nodes = []
-					add_parents(graph_key, True)
-			else:
-				display_list.append((x, depth, True))
-		mylist = display_list
-		for x in unsatisfied_blockers:
-			mylist.append((x, 0, True))
-
-		last_merge_depth = 0
-		for i in xrange(len(mylist)-1,-1,-1):
-			graph_key, depth, ordered = mylist[i]
-			if not ordered and depth == 0 and i > 0 \
-				and graph_key == mylist[i-1][0] and \
-				mylist[i-1][1] == 0:
-				# An ordered node got a consecutive duplicate when the tree was
-				# being filled in.
-				del mylist[i]
-				continue
-			if ordered and graph_key[-1] != "nomerge":
-				last_merge_depth = depth
-				continue
-			if depth >= last_merge_depth or \
-				i < len(mylist) - 1 and \
-				depth >= mylist[i+1][1]:
-					del mylist[i]
-
-		from portage import flatten
-		from portage.dep import use_reduce, paren_reduce
-		# files to fetch list - avoids counting a same file twice
-		# in size display (verbose mode)
-		myfetchlist=[]
-
-		# Use this set to detect when all the "repoadd" strings are "[0]"
-		# and disable the entire repo display in this case.
-		repoadd_set = set()
-
-		for mylist_index in xrange(len(mylist)):
-			x, depth, ordered = mylist[mylist_index]
-			pkg_type = x[0]
-			myroot = x[1]
-			pkg_key = x[2]
-			portdb = self.trees[myroot]["porttree"].dbapi
-			bindb  = self.trees[myroot]["bintree"].dbapi
-			vardb = self.trees[myroot]["vartree"].dbapi
-			vartree = self.trees[myroot]["vartree"]
-			pkgsettings = self.pkgsettings[myroot]
-
-			fetch=" "
-			indent = " " * depth
-
-			if isinstance(x, Blocker):
-				if x.satisfied:
-					blocker_style = "PKG_BLOCKER_SATISFIED"
-					addl = "%s  %s  " % (colorize(blocker_style, "b"), fetch)
-				else:
-					blocker_style = "PKG_BLOCKER"
-					addl = "%s  %s  " % (colorize(blocker_style, "B"), fetch)
-				if ordered:
-					counters.blocks += 1
-					if x.satisfied:
-						counters.blocks_satisfied += 1
-				resolved = portage.key_expand(
-					str(x.atom).lstrip("!"), mydb=vardb, settings=pkgsettings)
-				if "--columns" in self.myopts and "--quiet" in self.myopts:
-					addl += " " + colorize(blocker_style, resolved)
-				else:
-					addl = "[%s %s] %s%s" % \
-						(colorize(blocker_style, "blocks"),
-						addl, indent, colorize(blocker_style, resolved))
-				block_parents = self._blocker_parents.parent_nodes(x)
-				block_parents = set([pnode[2] for pnode in block_parents])
-				block_parents = ", ".join(block_parents)
-				if resolved!=x[2]:
-					addl += colorize(blocker_style,
-						" (\"%s\" is blocking %s)") % \
-						(str(x.atom).lstrip("!"), block_parents)
-				else:
-					addl += colorize(blocker_style,
-						" (is blocking %s)") % block_parents
-				if isinstance(x, Blocker) and x.satisfied:
-					if columns:
-						continue
-					p.append(addl)
-				else:
-					blockers.append(addl)
-			else:
-				pkg_status = x[3]
-				pkg_merge = ordered and pkg_status == "merge"
-				if not pkg_merge and pkg_status == "merge":
-					pkg_status = "nomerge"
-				built = pkg_type != "ebuild"
-				installed = pkg_type == "installed"
-				pkg = x
-				metadata = pkg.metadata
-				ebuild_path = None
-				repo_name = metadata["repository"]
-				if pkg_type == "ebuild":
-					ebuild_path = portdb.findname(pkg_key)
-					if not ebuild_path: # shouldn't happen
-						raise portage.exception.PackageNotFound(pkg_key)
-					repo_path_real = os.path.dirname(os.path.dirname(
-						os.path.dirname(ebuild_path)))
-				else:
-					repo_path_real = portdb.getRepositoryPath(repo_name)
-				pkg_use = list(pkg.use.enabled)
-				try:
-					restrict = flatten(use_reduce(paren_reduce(
-						pkg.metadata["RESTRICT"]), uselist=pkg_use))
-				except portage.exception.InvalidDependString, e:
-					if not pkg.installed:
-						show_invalid_depstring_notice(x,
-							pkg.metadata["RESTRICT"], str(e))
-						del e
-						return 1
-					restrict = []
-				if "ebuild" == pkg_type and x[3] != "nomerge" and \
-					"fetch" in restrict:
-					fetch = red("F")
-					if ordered:
-						counters.restrict_fetch += 1
-					if portdb.fetch_check(pkg_key, pkg_use):
-						fetch = green("f")
-						if ordered:
-							counters.restrict_fetch_satisfied += 1
-
-				#we need to use "--emptrytree" testing here rather than "empty" param testing because "empty"
-				#param is used for -u, where you still *do* want to see when something is being upgraded.
-				myoldbest = []
-				myinslotlist = None
-				installed_versions = vardb.match(portage.cpv_getkey(pkg_key))
-				if vardb.cpv_exists(pkg_key):
-					addl="  "+yellow("R")+fetch+"  "
-					if ordered:
-						if pkg_merge:
-							counters.reinst += 1
-						elif pkg_status == "uninstall":
-							counters.uninst += 1
-				# filter out old-style virtual matches
-				elif installed_versions and \
-					portage.cpv_getkey(installed_versions[0]) == \
-					portage.cpv_getkey(pkg_key):
-					myinslotlist = vardb.match(pkg.slot_atom)
-					# If this is the first install of a new-style virtual, we
-					# need to filter out old-style virtual matches.
-					if myinslotlist and \
-						portage.cpv_getkey(myinslotlist[0]) != \
-						portage.cpv_getkey(pkg_key):
-						myinslotlist = None
-					if myinslotlist:
-						myoldbest = myinslotlist[:]
-						addl = "   " + fetch
-						if not portage.dep.cpvequal(pkg_key,
-							portage.best([pkg_key] + myoldbest)):
-							# Downgrade in slot
-							addl += turquoise("U")+blue("D")
-							if ordered:
-								counters.downgrades += 1
-						else:
-							# Update in slot
-							addl += turquoise("U") + " "
-							if ordered:
-								counters.upgrades += 1
-					else:
-						# New slot, mark it new.
-						addl = " " + green("NS") + fetch + "  "
-						myoldbest = vardb.match(portage.cpv_getkey(pkg_key))
-						if ordered:
-							counters.newslot += 1
-
-					if "--changelog" in self.myopts:
-						inst_matches = vardb.match(pkg.slot_atom)
-						if inst_matches:
-							changelogs.extend(self.calc_changelog(
-								portdb.findname(pkg_key),
-								inst_matches[0], pkg_key))
-				else:
-					addl = " " + green("N") + " " + fetch + "  "
-					if ordered:
-						counters.new += 1
-
-				verboseadd = ""
-				repoadd = None
-
-				if True:
-					# USE flag display
-					forced_flags = set()
-					pkgsettings.setcpv(pkg) # for package.use.{mask,force}
-					forced_flags.update(pkgsettings.useforce)
-					forced_flags.update(pkgsettings.usemask)
-
-					cur_use = [flag for flag in pkg.use.enabled \
-						if flag in pkg.iuse.all]
-					cur_iuse = sorted(pkg.iuse.all)
-
-					if myoldbest and myinslotlist:
-						previous_cpv = myoldbest[0]
-					else:
-						previous_cpv = pkg.cpv
-					if vardb.cpv_exists(previous_cpv):
-						old_iuse, old_use = vardb.aux_get(
-								previous_cpv, ["IUSE", "USE"])
-						old_iuse = list(set(
-							filter_iuse_defaults(old_iuse.split())))
-						old_iuse.sort()
-						old_use = old_use.split()
-						is_new = False
-					else:
-						old_iuse = []
-						old_use = []
-						is_new = True
-
-					old_use = [flag for flag in old_use if flag in old_iuse]
-
-					use_expand = pkgsettings["USE_EXPAND"].lower().split()
-					use_expand.sort()
-					use_expand.reverse()
-					use_expand_hidden = \
-						pkgsettings["USE_EXPAND_HIDDEN"].lower().split()
-
-					def map_to_use_expand(myvals, forcedFlags=False,
-						removeHidden=True):
-						ret = {}
-						forced = {}
-						for exp in use_expand:
-							ret[exp] = []
-							forced[exp] = set()
-							for val in myvals[:]:
-								if val.startswith(exp.lower()+"_"):
-									if val in forced_flags:
-										forced[exp].add(val[len(exp)+1:])
-									ret[exp].append(val[len(exp)+1:])
-									myvals.remove(val)
-						ret["USE"] = myvals
-						forced["USE"] = [val for val in myvals \
-							if val in forced_flags]
-						if removeHidden:
-							for exp in use_expand_hidden:
-								ret.pop(exp, None)
-						if forcedFlags:
-							return ret, forced
-						return ret
-
-					# Prevent USE_EXPAND_HIDDEN flags from being hidden if they
-					# are the only thing that triggered reinstallation.
-					reinst_flags_map = {}
-					reinstall_for_flags = self._reinstall_nodes.get(pkg)
-					reinst_expand_map = None
-					if reinstall_for_flags:
-						reinst_flags_map = map_to_use_expand(
-							list(reinstall_for_flags), removeHidden=False)
-						for k in list(reinst_flags_map):
-							if not reinst_flags_map[k]:
-								del reinst_flags_map[k]
-						if not reinst_flags_map.get("USE"):
-							reinst_expand_map = reinst_flags_map.copy()
-							reinst_expand_map.pop("USE", None)
-					if reinst_expand_map and \
-						not set(reinst_expand_map).difference(
-						use_expand_hidden):
-						use_expand_hidden = \
-							set(use_expand_hidden).difference(
-							reinst_expand_map)
-
-					cur_iuse_map, iuse_forced = \
-						map_to_use_expand(cur_iuse, forcedFlags=True)
-					cur_use_map = map_to_use_expand(cur_use)
-					old_iuse_map = map_to_use_expand(old_iuse)
-					old_use_map = map_to_use_expand(old_use)
-
-					use_expand.sort()
-					use_expand.insert(0, "USE")
-					
-					for key in use_expand:
-						if key in use_expand_hidden:
-							continue
-						verboseadd += create_use_string(key.upper(),
-							cur_iuse_map[key], iuse_forced[key],
-							cur_use_map[key], old_iuse_map[key],
-							old_use_map[key], is_new,
-							reinst_flags_map.get(key))
-
-				if verbosity == 3:
-					# size verbose
-					mysize=0
-					if pkg_type == "ebuild" and pkg_merge:
-						try:
-							myfilesdict = portdb.getfetchsizes(pkg_key,
-								useflags=pkg_use, debug=self.edebug)
-						except portage.exception.InvalidDependString, e:
-							src_uri = portdb.aux_get(pkg_key, ["SRC_URI"])[0]
-							show_invalid_depstring_notice(x, src_uri, str(e))
-							del e
-							return 1
-						if myfilesdict is None:
-							myfilesdict="[empty/missing/bad digest]"
-						else:
-							for myfetchfile in myfilesdict:
-								if myfetchfile not in myfetchlist:
-									mysize+=myfilesdict[myfetchfile]
-									myfetchlist.append(myfetchfile)
-							if ordered:
-								counters.totalsize += mysize
-						verboseadd += format_size(mysize)
-
-					# overlay verbose
-					# assign index for a previous version in the same slot
-					has_previous = False
-					repo_name_prev = None
-					slot_atom = "%s:%s" % (portage.dep_getkey(pkg_key),
-						metadata["SLOT"])
-					slot_matches = vardb.match(slot_atom)
-					if slot_matches:
-						has_previous = True
-						repo_name_prev = vardb.aux_get(slot_matches[0],
-							["repository"])[0]
-
-					# now use the data to generate output
-					if pkg.installed or not has_previous:
-						repoadd = repo_display.repoStr(repo_path_real)
-					else:
-						repo_path_prev = None
-						if repo_name_prev:
-							repo_path_prev = portdb.getRepositoryPath(
-								repo_name_prev)
-						if repo_path_prev == repo_path_real:
-							repoadd = repo_display.repoStr(repo_path_real)
-						else:
-							repoadd = "%s=>%s" % (
-								repo_display.repoStr(repo_path_prev),
-								repo_display.repoStr(repo_path_real))
-					if repoadd:
-						repoadd_set.add(repoadd)
-
-				xs = [portage.cpv_getkey(pkg_key)] + \
-					list(portage.catpkgsplit(pkg_key)[2:])
-				if xs[2] == "r0":
-					xs[2] = ""
-				else:
-					xs[2] = "-" + xs[2]
-
-				mywidth = 130
-				if "COLUMNWIDTH" in self.settings:
-					try:
-						mywidth = int(self.settings["COLUMNWIDTH"])
-					except ValueError, e:
-						portage.writemsg("!!! %s\n" % str(e), noiselevel=-1)
-						portage.writemsg(
-							"!!! Unable to parse COLUMNWIDTH='%s'\n" % \
-							self.settings["COLUMNWIDTH"], noiselevel=-1)
-						del e
-				oldlp = mywidth - 30
-				newlp = oldlp - 30
-
-				# Convert myoldbest from a list to a string.
-				if not myoldbest:
-					myoldbest = ""
-				else:
-					for pos, key in enumerate(myoldbest):
-						key = portage.catpkgsplit(key)[2] + \
-							"-" + portage.catpkgsplit(key)[3]
-						if key[-3:] == "-r0":
-							key = key[:-3]
-						myoldbest[pos] = key
-					myoldbest = blue("["+", ".join(myoldbest)+"]")
-
-				pkg_cp = xs[0]
-				root_config = self.roots[myroot]
-				system_set = root_config.sets["system"]
-				world_set  = root_config.sets["world"]
-
-				pkg_system = False
-				pkg_world = False
-				try:
-					pkg_system = system_set.findAtomForPackage(pkg)
-					pkg_world  = world_set.findAtomForPackage(pkg)
-					if not (oneshot or pkg_world) and \
-						myroot == self.target_root and \
-						favorites_set.findAtomForPackage(pkg):
-						# Maybe it will be added to world now.
-						if create_world_atom(pkg, favorites_set, root_config):
-							pkg_world = True
-				except portage.exception.InvalidDependString:
-					# This is reported elsewhere if relevant.
-					pass
-
-				def pkgprint(pkg_str):
-					if pkg_merge:
-						if pkg_system:
-							return colorize("PKG_MERGE_SYSTEM", pkg_str)
-						elif pkg_world:
-							return colorize("PKG_MERGE_WORLD", pkg_str)
-						else:
-							return colorize("PKG_MERGE", pkg_str)
-					elif pkg_status == "uninstall":
-						return colorize("PKG_UNINSTALL", pkg_str)
-					else:
-						if pkg_system:
-							return colorize("PKG_NOMERGE_SYSTEM", pkg_str)
-						elif pkg_world:
-							return colorize("PKG_NOMERGE_WORLD", pkg_str)
-						else:
-							return colorize("PKG_NOMERGE", pkg_str)
-
-				try:
-					properties = flatten(use_reduce(paren_reduce(
-						pkg.metadata["PROPERTIES"]), uselist=pkg.use.enabled))
-				except portage.exception.InvalidDependString, e:
-					if not pkg.installed:
-						show_invalid_depstring_notice(pkg,
-							pkg.metadata["PROPERTIES"], str(e))
-						del e
-						return 1
-					properties = []
-				interactive = "interactive" in properties
-				if interactive and pkg.operation == "merge":
-					addl = colorize("WARN", "I") + addl[1:]
-					if ordered:
-						counters.interactive += 1
-
-				if x[1]!="/":
-					if myoldbest:
-						myoldbest +=" "
-					if "--columns" in self.myopts:
-						if "--quiet" in self.myopts:
-							myprint=addl+" "+indent+pkgprint(pkg_cp)
-							myprint=myprint+darkblue(" "+xs[1]+xs[2])+" "
-							myprint=myprint+myoldbest
-							myprint=myprint+darkgreen("to "+x[1])
-							verboseadd = None
-						else:
-							if not pkg_merge:
-								myprint = "[%s] %s%s" % \
-									(pkgprint(pkg_status.ljust(13)),
-									indent, pkgprint(pkg.cp))
-							else:
-								myprint = "[%s %s] %s%s" % \
-									(pkgprint(pkg.type_name), addl,
-									indent, pkgprint(pkg.cp))
-							if (newlp-nc_len(myprint)) > 0:
-								myprint=myprint+(" "*(newlp-nc_len(myprint)))
-							myprint=myprint+"["+darkblue(xs[1]+xs[2])+"] "
-							if (oldlp-nc_len(myprint)) > 0:
-								myprint=myprint+" "*(oldlp-nc_len(myprint))
-							myprint=myprint+myoldbest
-							myprint += darkgreen("to " + pkg.root)
-					else:
-						if not pkg_merge:
-							myprint = "[%s] " % pkgprint(pkg_status.ljust(13))
-						else:
-							myprint = "[%s %s] " % (pkgprint(pkg_type), addl)
-						myprint += indent + pkgprint(pkg_key) + " " + \
-							myoldbest + darkgreen("to " + myroot)
-				else:
-					if "--columns" in self.myopts:
-						if "--quiet" in self.myopts:
-							myprint=addl+" "+indent+pkgprint(pkg_cp)
-							myprint=myprint+" "+green(xs[1]+xs[2])+" "
-							myprint=myprint+myoldbest
-							verboseadd = None
-						else:
-							if not pkg_merge:
-								myprint = "[%s] %s%s" % \
-									(pkgprint(pkg_status.ljust(13)),
-									indent, pkgprint(pkg.cp))
-							else:
-								myprint = "[%s %s] %s%s" % \
-									(pkgprint(pkg.type_name), addl,
-									indent, pkgprint(pkg.cp))
-							if (newlp-nc_len(myprint)) > 0:
-								myprint=myprint+(" "*(newlp-nc_len(myprint)))
-							myprint=myprint+green(" ["+xs[1]+xs[2]+"] ")
-							if (oldlp-nc_len(myprint)) > 0:
-								myprint=myprint+(" "*(oldlp-nc_len(myprint)))
-							myprint += myoldbest
-					else:
-						if not pkg_merge:
-							myprint = "[%s] %s%s %s" % \
-								(pkgprint(pkg_status.ljust(13)),
-								indent, pkgprint(pkg.cpv),
-								myoldbest)
-						else:
-							myprint = "[%s %s] %s%s %s" % \
-								(pkgprint(pkg_type), addl, indent,
-								pkgprint(pkg.cpv), myoldbest)
-
-				if columns and pkg.operation == "uninstall":
-					continue
-				p.append((myprint, verboseadd, repoadd))
-
-				if "--tree" not in self.myopts and \
-					"--quiet" not in self.myopts and \
-					not self._opts_no_restart.intersection(self.myopts) and \
-					pkg.root == self._running_root.root and \
-					portage.match_from_list(
-					portage.const.PORTAGE_PACKAGE_ATOM, [pkg]) and \
-					not vardb.cpv_exists(pkg.cpv) and \
-					"--quiet" not in self.myopts:
-						if mylist_index < len(mylist) - 1:
-							p.append(colorize("WARN", "*** Portage will stop merging at this point and reload itself,"))
-							p.append(colorize("WARN", "    then resume the merge."))
-
-		out = sys.stdout
-		show_repos = repoadd_set and repoadd_set != set(["0"])
-
-		for x in p:
-			if isinstance(x, basestring):
-				out.write("%s\n" % (x,))
-				continue
-
-			myprint, verboseadd, repoadd = x
-
-			if verboseadd:
-				myprint += " " + verboseadd
-
-			if show_repos and repoadd:
-				myprint += " " + teal("[%s]" % repoadd)
-
-			out.write("%s\n" % (myprint,))
-
-		for x in blockers:
-			print x
-
-		if verbosity == 3:
-			print
-			print counters
-			if show_repos:
-				sys.stdout.write(str(repo_display))
-
-		if "--changelog" in self.myopts:
-			print
-			for revision,text in changelogs:
-				print bold('*'+revision)
-				sys.stdout.write(text)
-
-		sys.stdout.flush()
-		return os.EX_OK
-
-	def display_problems(self):
-		"""
-		Display problems with the dependency graph such as slot collisions.
-		This is called internally by display() to show the problems _after_
-		the merge list where it is most likely to be seen, but if display()
-		is not going to be called then this method should be called explicitly
-		to ensure that the user is notified of problems with the graph.
-
-		All output goes to stderr, except for unsatisfied dependencies which
-		go to stdout for parsing by programs such as autounmask.
-		"""
-
-		# Note that show_masked_packages() sends it's output to
-		# stdout, and some programs such as autounmask parse the
-		# output in cases when emerge bails out. However, when
-		# show_masked_packages() is called for installed packages
-		# here, the message is a warning that is more appropriate
-		# to send to stderr, so temporarily redirect stdout to
-		# stderr. TODO: Fix output code so there's a cleaner way
-		# to redirect everything to stderr.
-		sys.stdout.flush()
-		sys.stderr.flush()
-		stdout = sys.stdout
-		try:
-			sys.stdout = sys.stderr
-			self._display_problems()
-		finally:
-			sys.stdout = stdout
-			sys.stdout.flush()
-			sys.stderr.flush()
-
-		# This goes to stdout for parsing by programs like autounmask.
-		for pargs, kwargs in self._unsatisfied_deps_for_display:
-			self._show_unsatisfied_dep(*pargs, **kwargs)
-
-	def _display_problems(self):
-		if self._circular_deps_for_display is not None:
-			self._show_circular_deps(
-				self._circular_deps_for_display)
-
-		# The user is only notified of a slot conflict if
-		# there are no unresolvable blocker conflicts.
-		if self._unsatisfied_blockers_for_display is not None:
-			self._show_unsatisfied_blockers(
-				self._unsatisfied_blockers_for_display)
-		else:
-			self._show_slot_collision_notice()
-
-		# TODO: Add generic support for "set problem" handlers so that
-		# the below warnings aren't special cases for world only.
-
-		if self._missing_args:
-			world_problems = False
-			if "world" in self._sets:
-				# Filter out indirect members of world (from nested sets)
-				# since only direct members of world are desired here.
-				world_set = self.roots[self.target_root].sets["world"]
-				for arg, atom in self._missing_args:
-					if arg.name == "world" and atom in world_set:
-						world_problems = True
-						break
-
-			if world_problems:
-				sys.stderr.write("\n!!! Problems have been " + \
-					"detected with your world file\n")
-				sys.stderr.write("!!! Please run " + \
-					green("emaint --check world")+"\n\n")
-
-		if self._missing_args:
-			sys.stderr.write("\n" + colorize("BAD", "!!!") + \
-				" Ebuilds for the following packages are either all\n")
-			sys.stderr.write(colorize("BAD", "!!!") + \
-				" masked or don't exist:\n")
-			sys.stderr.write(" ".join(str(atom) for arg, atom in \
-				self._missing_args) + "\n")
-
-		if self._pprovided_args:
-			arg_refs = {}
-			for arg, atom in self._pprovided_args:
-				if isinstance(arg, SetArg):
-					parent = arg.name
-					arg_atom = (atom, atom)
-				else:
-					parent = "args"
-					arg_atom = (arg.arg, atom)
-				refs = arg_refs.setdefault(arg_atom, [])
-				if parent not in refs:
-					refs.append(parent)
-			msg = []
-			msg.append(bad("\nWARNING: "))
-			if len(self._pprovided_args) > 1:
-				msg.append("Requested packages will not be " + \
-					"merged because they are listed in\n")
-			else:
-				msg.append("A requested package will not be " + \
-					"merged because it is listed in\n")
-			msg.append("package.provided:\n\n")
-			problems_sets = set()
-			for (arg, atom), refs in arg_refs.iteritems():
-				ref_string = ""
-				if refs:
-					problems_sets.update(refs)
-					refs.sort()
-					ref_string = ", ".join(["'%s'" % name for name in refs])
-					ref_string = " pulled in by " + ref_string
-				msg.append("  %s%s\n" % (colorize("INFORM", str(arg)), ref_string))
-			msg.append("\n")
-			if "world" in problems_sets:
-				msg.append("This problem can be solved in one of the following ways:\n\n")
-				msg.append("  A) Use emaint to clean offending packages from world (if not installed).\n")
-				msg.append("  B) Uninstall offending packages (cleans them from world).\n")
-				msg.append("  C) Remove offending entries from package.provided.\n\n")
-				msg.append("The best course of action depends on the reason that an offending\n")
-				msg.append("package.provided entry exists.\n\n")
-			sys.stderr.write("".join(msg))
-
-		masked_packages = []
-		for pkg in self._masked_installed:
-			root_config = pkg.root_config
-			pkgsettings = self.pkgsettings[pkg.root]
-			mreasons = get_masking_status(pkg, pkgsettings, root_config)
-			masked_packages.append((root_config, pkgsettings,
-				pkg.cpv, pkg.metadata, mreasons))
-		if masked_packages:
-			sys.stderr.write("\n" + colorize("BAD", "!!!") + \
-				" The following installed packages are masked:\n")
-			show_masked_packages(masked_packages)
-			show_mask_docs()
-			print
-
-	def calc_changelog(self,ebuildpath,current,next):
-		if ebuildpath == None or not os.path.exists(ebuildpath):
-			return []
-		current = '-'.join(portage.catpkgsplit(current)[1:])
-		if current.endswith('-r0'):
-			current = current[:-3]
-		next = '-'.join(portage.catpkgsplit(next)[1:])
-		if next.endswith('-r0'):
-			next = next[:-3]
-		changelogpath = os.path.join(os.path.split(ebuildpath)[0],'ChangeLog')
-		try:
-			changelog = open(changelogpath).read()
-		except SystemExit, e:
-			raise # Needed else can't exit
-		except:
-			return []
-		divisions = self.find_changelog_tags(changelog)
-		#print 'XX from',current,'to',next
-		#for div,text in divisions: print 'XX',div
-		# skip entries for all revisions above the one we are about to emerge
-		for i in range(len(divisions)):
-			if divisions[i][0]==next:
-				divisions = divisions[i:]
-				break
-		# find out how many entries we are going to display
-		for i in range(len(divisions)):
-			if divisions[i][0]==current:
-				divisions = divisions[:i]
-				break
-		else:
-		    # couldnt find the current revision in the list. display nothing
-			return []
-		return divisions
-
-	def find_changelog_tags(self,changelog):
-		divs = []
-		release = None
-		while 1:
-			match = re.search(r'^\*\ ?([-a-zA-Z0-9_.+]*)(?:\ .*)?\n',changelog,re.M)
-			if match is None:
-				if release is not None:
-					divs.append((release,changelog))
-				return divs
-			if release is not None:
-				divs.append((release,changelog[:match.start()]))
-			changelog = changelog[match.end():]
-			release = match.group(1)
-			if release.endswith('.ebuild'):
-				release = release[:-7]
-			if release.endswith('-r0'):
-				release = release[:-3]
-
-	def saveNomergeFavorites(self):
-		"""Find atoms in favorites that are not in the mergelist and add them
-		to the world file if necessary."""
-		for x in ("--buildpkgonly", "--fetchonly", "--fetch-all-uri",
-			"--oneshot", "--onlydeps", "--pretend"):
-			if x in self.myopts:
-				return
-		root_config = self.roots[self.target_root]
-		world_set = root_config.sets["world"]
-
-		world_locked = False
-		if hasattr(world_set, "lock"):
-			world_set.lock()
-			world_locked = True
-
-		if hasattr(world_set, "load"):
-			world_set.load() # maybe it's changed on disk
-
-		args_set = self._sets["args"]
-		portdb = self.trees[self.target_root]["porttree"].dbapi
-		added_favorites = set()
-		for x in self._set_nodes:
-			pkg_type, root, pkg_key, pkg_status = x
-			if pkg_status != "nomerge":
-				continue
-
-			try:
-				myfavkey = create_world_atom(x, args_set, root_config)
-				if myfavkey:
-					if myfavkey in added_favorites:
-						continue
-					added_favorites.add(myfavkey)
-			except portage.exception.InvalidDependString, e:
-				writemsg("\n\n!!! '%s' has invalid PROVIDE: %s\n" % \
-					(pkg_key, str(e)), noiselevel=-1)
-				writemsg("!!! see '%s'\n\n" % os.path.join(
-					root, portage.VDB_PATH, pkg_key, "PROVIDE"), noiselevel=-1)
-				del e
-		all_added = []
-		for k in self._sets:
-			if k in ("args", "world") or not root_config.sets[k].world_candidate:
-				continue
-			s = SETPREFIX + k
-			if s in world_set:
-				continue
-			all_added.append(SETPREFIX + k)
-		all_added.extend(added_favorites)
-		all_added.sort()
-		for a in all_added:
-			print ">>> Recording %s in \"world\" favorites file..." % \
-				colorize("INFORM", str(a))
-		if all_added:
-			world_set.update(all_added)
-
-		if world_locked:
-			world_set.unlock()
-
-	def loadResumeCommand(self, resume_data, skip_masked=True,
-		skip_missing=True):
-		"""
-		Add a resume command to the graph and validate it in the process.  This
-		will raise a PackageNotFound exception if a package is not available.
-		"""
-
-		if not isinstance(resume_data, dict):
-			return False
-
-		mergelist = resume_data.get("mergelist")
-		if not isinstance(mergelist, list):
-			mergelist = []
-
-		fakedb = self.mydbapi
-		trees = self.trees
-		serialized_tasks = []
-		masked_tasks = []
-		for x in mergelist:
-			if not (isinstance(x, list) and len(x) == 4):
-				continue
-			pkg_type, myroot, pkg_key, action = x
-			if pkg_type not in self.pkg_tree_map:
-				continue
-			if action != "merge":
-				continue
-			tree_type = self.pkg_tree_map[pkg_type]
-			mydb = trees[myroot][tree_type].dbapi
-			db_keys = list(self._trees_orig[myroot][
-				tree_type].dbapi._aux_cache_keys)
-			try:
-				metadata = izip(db_keys, mydb.aux_get(pkg_key, db_keys))
-			except KeyError:
-				# It does no exist or it is corrupt.
-				if action == "uninstall":
-					continue
-				if skip_missing:
-					# TODO: log these somewhere
-					continue
-				raise portage.exception.PackageNotFound(pkg_key)
-			installed = action == "uninstall"
-			built = pkg_type != "ebuild"
-			root_config = self.roots[myroot]
-			pkg = Package(built=built, cpv=pkg_key,
-				installed=installed, metadata=metadata,
-				operation=action, root_config=root_config,
-				type_name=pkg_type)
-			if pkg_type == "ebuild":
-				pkgsettings = self.pkgsettings[myroot]
-				pkgsettings.setcpv(pkg)
-				pkg.metadata["USE"] = pkgsettings["PORTAGE_USE"]
-				pkg.metadata['CHOST'] = pkgsettings.get('CHOST', '')
-			self._pkg_cache[pkg] = pkg
-
-			root_config = self.roots[pkg.root]
-			if "merge" == pkg.operation and \
-				not visible(root_config.settings, pkg):
-				if skip_masked:
-					masked_tasks.append(Dependency(root=pkg.root, parent=pkg))
-				else:
-					self._unsatisfied_deps_for_display.append(
-						((pkg.root, "="+pkg.cpv), {"myparent":None}))
-
-			fakedb[myroot].cpv_inject(pkg)
-			serialized_tasks.append(pkg)
-			self.spinner.update()
-
-		if self._unsatisfied_deps_for_display:
-			return False
-
-		if not serialized_tasks or "--nodeps" in self.myopts:
-			self._serialized_tasks_cache = serialized_tasks
-			self._scheduler_graph = self.digraph
-		else:
-			self._select_package = self._select_pkg_from_graph
-			self.myparams.add("selective")
-			# Always traverse deep dependencies in order to account for
-			# potentially unsatisfied dependencies of installed packages.
-			# This is necessary for correct --keep-going or --resume operation
-			# in case a package from a group of circularly dependent packages
-			# fails. In this case, a package which has recently been installed
-			# may have an unsatisfied circular dependency (pulled in by
-			# PDEPEND, for example). So, even though a package is already
-			# installed, it may not have all of it's dependencies satisfied, so
-			# it may not be usable. If such a package is in the subgraph of
-			# deep depenedencies of a scheduled build, that build needs to
-			# be cancelled. In order for this type of situation to be
-			# recognized, deep traversal of dependencies is required.
-			self.myparams.add("deep")
-
-			favorites = resume_data.get("favorites")
-			args_set = self._sets["args"]
-			if isinstance(favorites, list):
-				args = self._load_favorites(favorites)
-			else:
-				args = []
-
-			for task in serialized_tasks:
-				if isinstance(task, Package) and \
-					task.operation == "merge":
-					if not self._add_pkg(task, None):
-						return False
-
-			# Packages for argument atoms need to be explicitly
-			# added via _add_pkg() so that they are included in the
-			# digraph (needed at least for --tree display).
-			for arg in args:
-				for atom in arg.set:
-					pkg, existing_node = self._select_package(
-						arg.root_config.root, atom)
-					if existing_node is None and \
-						pkg is not None:
-						if not self._add_pkg(pkg, Dependency(atom=atom,
-							root=pkg.root, parent=arg)):
-							return False
-
-			# Allow unsatisfied deps here to avoid showing a masking
-			# message for an unsatisfied dep that isn't necessarily
-			# masked.
-			if not self._create_graph(allow_unsatisfied=True):
-				return False
-
-			unsatisfied_deps = []
-			for dep in self._unsatisfied_deps:
-				if not isinstance(dep.parent, Package):
-					continue
-				if dep.parent.operation == "merge":
-					unsatisfied_deps.append(dep)
-					continue
-
-				# For unsatisfied deps of installed packages, only account for
-				# them if they are in the subgraph of dependencies of a package
-				# which is scheduled to be installed.
-				unsatisfied_install = False
-				traversed = set()
-				dep_stack = self.digraph.parent_nodes(dep.parent)
-				while dep_stack:
-					node = dep_stack.pop()
-					if not isinstance(node, Package):
-						continue
-					if node.operation == "merge":
-						unsatisfied_install = True
-						break
-					if node in traversed:
-						continue
-					traversed.add(node)
-					dep_stack.extend(self.digraph.parent_nodes(node))
-
-				if unsatisfied_install:
-					unsatisfied_deps.append(dep)
-
-			if masked_tasks or unsatisfied_deps:
-				# This probably means that a required package
-				# was dropped via --skipfirst. It makes the
-				# resume list invalid, so convert it to a
-				# UnsatisfiedResumeDep exception.
-				raise self.UnsatisfiedResumeDep(self,
-					masked_tasks + unsatisfied_deps)
-			self._serialized_tasks_cache = None
-			try:
-				self.altlist()
-			except self._unknown_internal_error:
-				return False
-
-		return True
-
-	def _load_favorites(self, favorites):
-		"""
-		Use a list of favorites to resume state from a
-		previous select_files() call. This creates similar
-		DependencyArg instances to those that would have
-		been created by the original select_files() call.
-		This allows Package instances to be matched with
-		DependencyArg instances during graph creation.
-		"""
-		root_config = self.roots[self.target_root]
-		getSetAtoms = root_config.setconfig.getSetAtoms
-		sets = root_config.sets
-		args = []
-		for x in favorites:
-			if not isinstance(x, basestring):
-				continue
-			if x in ("system", "world"):
-				x = SETPREFIX + x
-			if x.startswith(SETPREFIX):
-				s = x[len(SETPREFIX):]
-				if s not in sets:
-					continue
-				if s in self._sets:
-					continue
-				# Recursively expand sets so that containment tests in
-				# self._get_parent_sets() properly match atoms in nested
-				# sets (like if world contains system).
-				expanded_set = InternalPackageSet(
-					initial_atoms=getSetAtoms(s))
-				self._sets[s] = expanded_set
-				args.append(SetArg(arg=x, set=expanded_set,
-					root_config=root_config))
-			else:
-				if not portage.isvalidatom(x):
-					continue
-				args.append(AtomArg(arg=x, atom=x,
-					root_config=root_config))
-
-		self._set_args(args)
-		return args
-
-	class UnsatisfiedResumeDep(portage.exception.PortageException):
-		"""
-		A dependency of a resume list is not installed. This
-		can occur when a required package is dropped from the
-		merge list via --skipfirst.
-		"""
-		def __init__(self, depgraph, value):
-			portage.exception.PortageException.__init__(self, value)
-			self.depgraph = depgraph
-
-	class _internal_exception(portage.exception.PortageException):
-		def __init__(self, value=""):
-			portage.exception.PortageException.__init__(self, value)
-
-	class _unknown_internal_error(_internal_exception):
-		"""
-		Used by the depgraph internally to terminate graph creation.
-		The specific reason for the failure should have been dumped
-		to stderr, unfortunately, the exact reason for the failure
-		may not be known.
-		"""
-
-	class _serialize_tasks_retry(_internal_exception):
-		"""
-		This is raised by the _serialize_tasks() method when it needs to
-		be called again for some reason. The only case that it's currently
-		used for is when neglected dependencies need to be added to the
-		graph in order to avoid making a potentially unsafe decision.
-		"""
-
-	class _dep_check_composite_db(portage.dbapi):
-		"""
-		A dbapi-like interface that is optimized for use in dep_check() calls.
-		This is built on top of the existing depgraph package selection logic.
-		Some packages that have been added to the graph may be masked from this
-		view in order to influence the atom preference selection that occurs
-		via dep_check().
-		"""
-		def __init__(self, depgraph, root):
-			portage.dbapi.__init__(self)
-			self._depgraph = depgraph
-			self._root = root
-			self._match_cache = {}
-			self._cpv_pkg_map = {}
-
-		def _clear_cache(self):
-			self._match_cache.clear()
-			self._cpv_pkg_map.clear()
-
-		def match(self, atom):
-			ret = self._match_cache.get(atom)
-			if ret is not None:
-				return ret[:]
-			orig_atom = atom
-			if "/" not in atom:
-				atom = self._dep_expand(atom)
-			pkg, existing = self._depgraph._select_package(self._root, atom)
-			if not pkg:
-				ret = []
-			else:
-				# Return the highest available from select_package() as well as
-				# any matching slots in the graph db.
-				slots = set()
-				slots.add(pkg.metadata["SLOT"])
-				atom_cp = portage.dep_getkey(atom)
-				if pkg.cp.startswith("virtual/"):
-					# For new-style virtual lookahead that occurs inside
-					# dep_check(), examine all slots. This is needed
-					# so that newer slots will not unnecessarily be pulled in
-					# when a satisfying lower slot is already installed. For
-					# example, if virtual/jdk-1.4 is satisfied via kaffe then
-					# there's no need to pull in a newer slot to satisfy a
-					# virtual/jdk dependency.
-					for db, pkg_type, built, installed, db_keys in \
-						self._depgraph._filtered_trees[self._root]["dbs"]:
-						for cpv in db.match(atom):
-							if portage.cpv_getkey(cpv) != pkg.cp:
-								continue
-							slots.add(db.aux_get(cpv, ["SLOT"])[0])
-				ret = []
-				if self._visible(pkg):
-					self._cpv_pkg_map[pkg.cpv] = pkg
-					ret.append(pkg.cpv)
-				slots.remove(pkg.metadata["SLOT"])
-				while slots:
-					slot_atom = "%s:%s" % (atom_cp, slots.pop())
-					pkg, existing = self._depgraph._select_package(
-						self._root, slot_atom)
-					if not pkg:
-						continue
-					if not self._visible(pkg):
-						continue
-					self._cpv_pkg_map[pkg.cpv] = pkg
-					ret.append(pkg.cpv)
-				if ret:
-					self._cpv_sort_ascending(ret)
-			self._match_cache[orig_atom] = ret
-			return ret[:]
-
-		def _visible(self, pkg):
-			if pkg.installed and "selective" not in self._depgraph.myparams:
-				try:
-					arg = self._depgraph._iter_atoms_for_pkg(pkg).next()
-				except (StopIteration, portage.exception.InvalidDependString):
-					arg = None
-				if arg:
-					return False
-			if pkg.installed:
-				try:
-					if not visible(
-						self._depgraph.pkgsettings[pkg.root], pkg):
-						return False
-				except portage.exception.InvalidDependString:
-					pass
-			in_graph = self._depgraph._slot_pkg_map[
-				self._root].get(pkg.slot_atom)
-			if in_graph is None:
-				# Mask choices for packages which are not the highest visible
-				# version within their slot (since they usually trigger slot
-				# conflicts).
-				highest_visible, in_graph = self._depgraph._select_package(
-					self._root, pkg.slot_atom)
-				if pkg != highest_visible:
-					return False
-			elif in_graph != pkg:
-				# Mask choices for packages that would trigger a slot
-				# conflict with a previously selected package.
-				return False
-			return True
-
-		def _dep_expand(self, atom):
-			"""
-			This is only needed for old installed packages that may
-			contain atoms that are not fully qualified with a specific
-			category. Emulate the cpv_expand() function that's used by
-			dbapi.match() in cases like this. If there are multiple
-			matches, it's often due to a new-style virtual that has
-			been added, so try to filter those out to avoid raising
-			a ValueError.
-			"""
-			root_config = self._depgraph.roots[self._root]
-			orig_atom = atom
-			expanded_atoms = self._depgraph._dep_expand(root_config, atom)
-			if len(expanded_atoms) > 1:
-				non_virtual_atoms = []
-				for x in expanded_atoms:
-					if not portage.dep_getkey(x).startswith("virtual/"):
-						non_virtual_atoms.append(x)
-				if len(non_virtual_atoms) == 1:
-					expanded_atoms = non_virtual_atoms
-			if len(expanded_atoms) > 1:
-				# compatible with portage.cpv_expand()
-				raise portage.exception.AmbiguousPackageName(
-					[portage.dep_getkey(x) for x in expanded_atoms])
-			if expanded_atoms:
-				atom = expanded_atoms[0]
-			else:
-				null_atom = insert_category_into_atom(atom, "null")
-				null_cp = portage.dep_getkey(null_atom)
-				cat, atom_pn = portage.catsplit(null_cp)
-				virts_p = root_config.settings.get_virts_p().get(atom_pn)
-				if virts_p:
-					# Allow the resolver to choose which virtual.
-					atom = insert_category_into_atom(atom, "virtual")
-				else:
-					atom = insert_category_into_atom(atom, "null")
-			return atom
-
-		def aux_get(self, cpv, wants):
-			metadata = self._cpv_pkg_map[cpv].metadata
-			return [metadata.get(x, "") for x in wants]
-
-class Scheduler(PollScheduler):
-
-	_opts_ignore_blockers = \
-		frozenset(["--buildpkgonly",
-		"--fetchonly", "--fetch-all-uri",
-		"--nodeps", "--pretend"])
-
-	_opts_no_background = \
-		frozenset(["--pretend",
-		"--fetchonly", "--fetch-all-uri"])
-
-	_opts_no_restart = frozenset(["--buildpkgonly",
-		"--fetchonly", "--fetch-all-uri", "--pretend"])
-
-	_bad_resume_opts = set(["--ask", "--changelog",
-		"--resume", "--skipfirst"])
-
-	_fetch_log = os.path.join(_emerge_log_dir, 'emerge-fetch.log')
-
-	class _iface_class(SlotObject):
-		__slots__ = ("dblinkEbuildPhase", "dblinkDisplayMerge",
-			"dblinkElog", "dblinkEmergeLog", "fetch", "register", "schedule",
-			"scheduleSetup", "scheduleUnpack", "scheduleYield",
-			"unregister")
-
-	class _fetch_iface_class(SlotObject):
-		__slots__ = ("log_file", "schedule")
-
-	_task_queues_class = slot_dict_class(
-		("merge", "jobs", "fetch", "unpack"), prefix="")
-
-	class _build_opts_class(SlotObject):
-		__slots__ = ("buildpkg", "buildpkgonly",
-			"fetch_all_uri", "fetchonly", "pretend")
-
-	class _binpkg_opts_class(SlotObject):
-		__slots__ = ("fetchonly", "getbinpkg", "pretend")
-
-	class _pkg_count_class(SlotObject):
-		__slots__ = ("curval", "maxval")
-
-	class _emerge_log_class(SlotObject):
-		__slots__ = ("xterm_titles",)
-
-		def log(self, *pargs, **kwargs):
-			if not self.xterm_titles:
-				# Avoid interference with the scheduler's status display.
-				kwargs.pop("short_msg", None)
-			emergelog(self.xterm_titles, *pargs, **kwargs)
-
-	class _failed_pkg(SlotObject):
-		__slots__ = ("build_dir", "build_log", "pkg", "returncode")
-
-	class _ConfigPool(object):
-		"""Interface for a task to temporarily allocate a config
-		instance from a pool. This allows a task to be constructed
-		long before the config instance actually becomes needed, like
-		when prefetchers are constructed for the whole merge list."""
-		__slots__ = ("_root", "_allocate", "_deallocate")
-		def __init__(self, root, allocate, deallocate):
-			self._root = root
-			self._allocate = allocate
-			self._deallocate = deallocate
-		def allocate(self):
-			return self._allocate(self._root)
-		def deallocate(self, settings):
-			self._deallocate(settings)
-
-	class _unknown_internal_error(portage.exception.PortageException):
-		"""
-		Used internally to terminate scheduling. The specific reason for
-		the failure should have been dumped to stderr.
-		"""
-		def __init__(self, value=""):
-			portage.exception.PortageException.__init__(self, value)
-
-	def __init__(self, settings, trees, mtimedb, myopts,
-		spinner, mergelist, favorites, digraph):
-		PollScheduler.__init__(self)
-		self.settings = settings
-		self.target_root = settings["ROOT"]
-		self.trees = trees
-		self.myopts = myopts
-		self._spinner = spinner
-		self._mtimedb = mtimedb
-		self._mergelist = mergelist
-		self._favorites = favorites
-		self._args_set = InternalPackageSet(favorites)
-		self._build_opts = self._build_opts_class()
-		for k in self._build_opts.__slots__:
-			setattr(self._build_opts, k, "--" + k.replace("_", "-") in myopts)
-		self._binpkg_opts = self._binpkg_opts_class()
-		for k in self._binpkg_opts.__slots__:
-			setattr(self._binpkg_opts, k, "--" + k.replace("_", "-") in myopts)
-
-		self.curval = 0
-		self._logger = self._emerge_log_class()
-		self._task_queues = self._task_queues_class()
-		for k in self._task_queues.allowed_keys:
-			setattr(self._task_queues, k,
-				SequentialTaskQueue())
-
-		# Holds merges that will wait to be executed when no builds are
-		# executing. This is useful for system packages since dependencies
-		# on system packages are frequently unspecified.
-		self._merge_wait_queue = []
-		# Holds merges that have been transfered from the merge_wait_queue to
-		# the actual merge queue. They are removed from this list upon
-		# completion. Other packages can start building only when this list is
-		# empty.
-		self._merge_wait_scheduled = []
-
-		# Holds system packages and their deep runtime dependencies. Before
-		# being merged, these packages go to merge_wait_queue, to be merged
-		# when no other packages are building.
-		self._deep_system_deps = set()
-
-		# Holds packages to merge which will satisfy currently unsatisfied
-		# deep runtime dependencies of system packages. If this is not empty
-		# then no parallel builds will be spawned until it is empty. This
-		# minimizes the possibility that a build will fail due to the system
-		# being in a fragile state. For example, see bug #259954.
-		self._unsatisfied_system_deps = set()
-
-		self._status_display = JobStatusDisplay(
-			xterm_titles=('notitles' not in settings.features))
-		self._max_load = myopts.get("--load-average")
-		max_jobs = myopts.get("--jobs")
-		if max_jobs is None:
-			max_jobs = 1
-		self._set_max_jobs(max_jobs)
-
-		# The root where the currently running
-		# portage instance is installed.
-		self._running_root = trees["/"]["root_config"]
-		self.edebug = 0
-		if settings.get("PORTAGE_DEBUG", "") == "1":
-			self.edebug = 1
-		self.pkgsettings = {}
-		self._config_pool = {}
-		self._blocker_db = {}
-		for root in trees:
-			self._config_pool[root] = []
-			self._blocker_db[root] = BlockerDB(trees[root]["root_config"])
-
-		fetch_iface = self._fetch_iface_class(log_file=self._fetch_log,
-			schedule=self._schedule_fetch)
-		self._sched_iface = self._iface_class(
-			dblinkEbuildPhase=self._dblink_ebuild_phase,
-			dblinkDisplayMerge=self._dblink_display_merge,
-			dblinkElog=self._dblink_elog,
-			dblinkEmergeLog=self._dblink_emerge_log,
-			fetch=fetch_iface, register=self._register,
-			schedule=self._schedule_wait,
-			scheduleSetup=self._schedule_setup,
-			scheduleUnpack=self._schedule_unpack,
-			scheduleYield=self._schedule_yield,
-			unregister=self._unregister)
-
-		self._prefetchers = weakref.WeakValueDictionary()
-		self._pkg_queue = []
-		self._completed_tasks = set()
-
-		self._failed_pkgs = []
-		self._failed_pkgs_all = []
-		self._failed_pkgs_die_msgs = []
-		self._post_mod_echo_msgs = []
-		self._parallel_fetch = False
-		merge_count = len([x for x in mergelist \
-			if isinstance(x, Package) and x.operation == "merge"])
-		self._pkg_count = self._pkg_count_class(
-			curval=0, maxval=merge_count)
-		self._status_display.maxval = self._pkg_count.maxval
-
-		# The load average takes some time to respond when new
-		# jobs are added, so we need to limit the rate of adding
-		# new jobs.
-		self._job_delay_max = 10
-		self._job_delay_factor = 1.0
-		self._job_delay_exp = 1.5
-		self._previous_job_start_time = None
-
-		self._set_digraph(digraph)
-
-		# This is used to memoize the _choose_pkg() result when
-		# no packages can be chosen until one of the existing
-		# jobs completes.
-		self._choose_pkg_return_early = False
-
-		features = self.settings.features
-		if "parallel-fetch" in features and \
-			not ("--pretend" in self.myopts or \
-			"--fetch-all-uri" in self.myopts or \
-			"--fetchonly" in self.myopts):
-			if "distlocks" not in features:
-				portage.writemsg(red("!!!")+"\n", noiselevel=-1)
-				portage.writemsg(red("!!!")+" parallel-fetching " + \
-					"requires the distlocks feature enabled"+"\n",
-					noiselevel=-1)
-				portage.writemsg(red("!!!")+" you have it disabled, " + \
-					"thus parallel-fetching is being disabled"+"\n",
-					noiselevel=-1)
-				portage.writemsg(red("!!!")+"\n", noiselevel=-1)
-			elif len(mergelist) > 1:
-				self._parallel_fetch = True
-
-		if self._parallel_fetch:
-				# clear out existing fetch log if it exists
-				try:
-					open(self._fetch_log, 'w')
-				except EnvironmentError:
-					pass
-
-		self._running_portage = None
-		portage_match = self._running_root.trees["vartree"].dbapi.match(
-			portage.const.PORTAGE_PACKAGE_ATOM)
-		if portage_match:
-			cpv = portage_match.pop()
-			self._running_portage = self._pkg(cpv, "installed",
-				self._running_root, installed=True)
-
-	def _poll(self, timeout=None):
-		self._schedule()
-		PollScheduler._poll(self, timeout=timeout)
-
-	def _set_max_jobs(self, max_jobs):
-		self._max_jobs = max_jobs
-		self._task_queues.jobs.max_jobs = max_jobs
-
-	def _background_mode(self):
-		"""
-		Check if background mode is enabled and adjust states as necessary.
-
-		@rtype: bool
-		@returns: True if background mode is enabled, False otherwise.
-		"""
-		background = (self._max_jobs is True or \
-			self._max_jobs > 1 or "--quiet" in self.myopts) and \
-			not bool(self._opts_no_background.intersection(self.myopts))
-
-		if background:
-			interactive_tasks = self._get_interactive_tasks()
-			if interactive_tasks:
-				background = False
-				writemsg_level(">>> Sending package output to stdio due " + \
-					"to interactive package(s):\n",
-					level=logging.INFO, noiselevel=-1)
-				msg = [""]
-				for pkg in interactive_tasks:
-					pkg_str = "  " + colorize("INFORM", str(pkg.cpv))
-					if pkg.root != "/":
-						pkg_str += " for " + pkg.root
-					msg.append(pkg_str)
-				msg.append("")
-				writemsg_level("".join("%s\n" % (l,) for l in msg),
-					level=logging.INFO, noiselevel=-1)
-				if self._max_jobs is True or self._max_jobs > 1:
-					self._set_max_jobs(1)
-					writemsg_level(">>> Setting --jobs=1 due " + \
-						"to the above interactive package(s)\n",
-						level=logging.INFO, noiselevel=-1)
-
-		self._status_display.quiet = \
-			not background or \
-			("--quiet" in self.myopts and \
-			"--verbose" not in self.myopts)
-
-		self._logger.xterm_titles = \
-			"notitles" not in self.settings.features and \
-			self._status_display.quiet
-
-		return background
-
-	def _get_interactive_tasks(self):
-		from portage import flatten
-		from portage.dep import use_reduce, paren_reduce
-		interactive_tasks = []
-		for task in self._mergelist:
-			if not (isinstance(task, Package) and \
-				task.operation == "merge"):
-				continue
-			try:
-				properties = flatten(use_reduce(paren_reduce(
-					task.metadata["PROPERTIES"]), uselist=task.use.enabled))
-			except portage.exception.InvalidDependString, e:
-				show_invalid_depstring_notice(task,
-					task.metadata["PROPERTIES"], str(e))
-				raise self._unknown_internal_error()
-			if "interactive" in properties:
-				interactive_tasks.append(task)
-		return interactive_tasks
-
-	def _set_digraph(self, digraph):
-		if "--nodeps" in self.myopts or \
-			(self._max_jobs is not True and self._max_jobs < 2):
-			# save some memory
-			self._digraph = None
-			return
-
-		self._digraph = digraph
-		self._find_system_deps()
-		self._prune_digraph()
-		self._prevent_builddir_collisions()
-
-	def _find_system_deps(self):
-		"""
-		Find system packages and their deep runtime dependencies. Before being
-		merged, these packages go to merge_wait_queue, to be merged when no
-		other packages are building.
-		"""
-		deep_system_deps = self._deep_system_deps
-		deep_system_deps.clear()
-		deep_system_deps.update(
-			_find_deep_system_runtime_deps(self._digraph))
-		deep_system_deps.difference_update([pkg for pkg in \
-			deep_system_deps if pkg.operation != "merge"])
-
-	def _prune_digraph(self):
-		"""
-		Prune any root nodes that are irrelevant.
-		"""
-
-		graph = self._digraph
-		completed_tasks = self._completed_tasks
-		removed_nodes = set()
-		while True:
-			for node in graph.root_nodes():
-				if not isinstance(node, Package) or \
-					(node.installed and node.operation == "nomerge") or \
-					node.onlydeps or \
-					node in completed_tasks:
-					removed_nodes.add(node)
-			if removed_nodes:
-				graph.difference_update(removed_nodes)
-			if not removed_nodes:
-				break
-			removed_nodes.clear()
-
-	def _prevent_builddir_collisions(self):
-		"""
-		When building stages, sometimes the same exact cpv needs to be merged
-		to both $ROOTs. Add edges to the digraph in order to avoid collisions
-		in the builddir. Currently, normal file locks would be inappropriate
-		for this purpose since emerge holds all of it's build dir locks from
-		the main process.
-		"""
-		cpv_map = {}
-		for pkg in self._mergelist:
-			if not isinstance(pkg, Package):
-				# a satisfied blocker
-				continue
-			if pkg.installed:
-				continue
-			if pkg.cpv not in cpv_map:
-				cpv_map[pkg.cpv] = [pkg]
-				continue
-			for earlier_pkg in cpv_map[pkg.cpv]:
-				self._digraph.add(earlier_pkg, pkg,
-					priority=DepPriority(buildtime=True))
-			cpv_map[pkg.cpv].append(pkg)
-
-	class _pkg_failure(portage.exception.PortageException):
-		"""
-		An instance of this class is raised by unmerge() when
-		an uninstallation fails.
-		"""
-		status = 1
-		def __init__(self, *pargs):
-			portage.exception.PortageException.__init__(self, pargs)
-			if pargs:
-				self.status = pargs[0]
-
-	def _schedule_fetch(self, fetcher):
-		"""
-		Schedule a fetcher on the fetch queue, in order to
-		serialize access to the fetch log.
-		"""
-		self._task_queues.fetch.addFront(fetcher)
-
-	def _schedule_setup(self, setup_phase):
-		"""
-		Schedule a setup phase on the merge queue, in order to
-		serialize unsandboxed access to the live filesystem.
-		"""
-		self._task_queues.merge.addFront(setup_phase)
-		self._schedule()
-
-	def _schedule_unpack(self, unpack_phase):
-		"""
-		Schedule an unpack phase on the unpack queue, in order
-		to serialize $DISTDIR access for live ebuilds.
-		"""
-		self._task_queues.unpack.add(unpack_phase)
-
-	def _find_blockers(self, new_pkg):
-		"""
-		Returns a callable which should be called only when
-		the vdb lock has been acquired.
-		"""
-		def get_blockers():
-			return self._find_blockers_with_lock(new_pkg, acquire_lock=0)
-		return get_blockers
-
-	def _find_blockers_with_lock(self, new_pkg, acquire_lock=0):
-		if self._opts_ignore_blockers.intersection(self.myopts):
-			return None
-
-		# Call gc.collect() here to avoid heap overflow that
-		# triggers 'Cannot allocate memory' errors (reported
-		# with python-2.5).
-		import gc
-		gc.collect()
-
-		blocker_db = self._blocker_db[new_pkg.root]
-
-		blocker_dblinks = []
-		for blocking_pkg in blocker_db.findInstalledBlockers(
-			new_pkg, acquire_lock=acquire_lock):
-			if new_pkg.slot_atom == blocking_pkg.slot_atom:
-				continue
-			if new_pkg.cpv == blocking_pkg.cpv:
-				continue
-			blocker_dblinks.append(portage.dblink(
-				blocking_pkg.category, blocking_pkg.pf, blocking_pkg.root,
-				self.pkgsettings[blocking_pkg.root], treetype="vartree",
-				vartree=self.trees[blocking_pkg.root]["vartree"]))
-
-		gc.collect()
-
-		return blocker_dblinks
-
-	def _dblink_pkg(self, pkg_dblink):
-		cpv = pkg_dblink.mycpv
-		type_name = RootConfig.tree_pkg_map[pkg_dblink.treetype]
-		root_config = self.trees[pkg_dblink.myroot]["root_config"]
-		installed = type_name == "installed"
-		return self._pkg(cpv, type_name, root_config, installed=installed)
-
-	def _append_to_log_path(self, log_path, msg):
-		f = open(log_path, 'a')
-		try:
-			f.write(msg)
-		finally:
-			f.close()
-
-	def _dblink_elog(self, pkg_dblink, phase, func, msgs):
-
-		log_path = pkg_dblink.settings.get("PORTAGE_LOG_FILE")
-		log_file = None
-		out = sys.stdout
-		background = self._background
-
-		if background and log_path is not None:
-			log_file = open(log_path, 'a')
-			out = log_file
-
-		try:
-			for msg in msgs:
-				func(msg, phase=phase, key=pkg_dblink.mycpv, out=out)
-		finally:
-			if log_file is not None:
-				log_file.close()
-
-	def _dblink_emerge_log(self, msg):
-		self._logger.log(msg)
-
-	def _dblink_display_merge(self, pkg_dblink, msg, level=0, noiselevel=0):
-		log_path = pkg_dblink.settings.get("PORTAGE_LOG_FILE")
-		background = self._background
-
-		if log_path is None:
-			if not (background and level < logging.WARN):
-				portage.util.writemsg_level(msg,
-					level=level, noiselevel=noiselevel)
-		else:
-			if not background:
-				portage.util.writemsg_level(msg,
-					level=level, noiselevel=noiselevel)
-			self._append_to_log_path(log_path, msg)
-
-	def _dblink_ebuild_phase(self,
-		pkg_dblink, pkg_dbapi, ebuild_path, phase):
-		"""
-		Using this callback for merge phases allows the scheduler
-		to run while these phases execute asynchronously, and allows
-		the scheduler control output handling.
-		"""
-
-		scheduler = self._sched_iface
-		settings = pkg_dblink.settings
-		pkg = self._dblink_pkg(pkg_dblink)
-		background = self._background
-		log_path = settings.get("PORTAGE_LOG_FILE")
-
-		ebuild_phase = EbuildPhase(background=background,
-			pkg=pkg, phase=phase, scheduler=scheduler,
-			settings=settings, tree=pkg_dblink.treetype)
-		ebuild_phase.start()
-		ebuild_phase.wait()
-
-		return ebuild_phase.returncode
-
-	def _generate_digests(self):
-		"""
-		Generate digests if necessary for --digests or FEATURES=digest.
-		In order to avoid interference, this must done before parallel
-		tasks are started.
-		"""
-
-		if '--fetchonly' in self.myopts:
-			return os.EX_OK
-
-		digest = '--digest' in self.myopts
-		if not digest:
-			for pkgsettings in self.pkgsettings.itervalues():
-				if 'digest' in pkgsettings.features:
-					digest = True
-					break
-
-		if not digest:
-			return os.EX_OK
-
-		for x in self._mergelist:
-			if not isinstance(x, Package) or \
-				x.type_name != 'ebuild' or \
-				x.operation != 'merge':
-				continue
-			pkgsettings = self.pkgsettings[x.root]
-			if '--digest' not in self.myopts and \
-				'digest' not in pkgsettings.features:
-				continue
-			portdb = x.root_config.trees['porttree'].dbapi
-			ebuild_path = portdb.findname(x.cpv)
-			if not ebuild_path:
-				writemsg_level(
-					"!!! Could not locate ebuild for '%s'.\n" \
-					% x.cpv, level=logging.ERROR, noiselevel=-1)
-				return 1
-			pkgsettings['O'] = os.path.dirname(ebuild_path)
-			if not portage.digestgen([], pkgsettings, myportdb=portdb):
-				writemsg_level(
-					"!!! Unable to generate manifest for '%s'.\n" \
-					% x.cpv, level=logging.ERROR, noiselevel=-1)
-				return 1
-
-		return os.EX_OK
-
-	def _check_manifests(self):
-		# Verify all the manifests now so that the user is notified of failure
-		# as soon as possible.
-		if "strict" not in self.settings.features or \
-			"--fetchonly" in self.myopts or \
-			"--fetch-all-uri" in self.myopts:
-			return os.EX_OK
-
-		shown_verifying_msg = False
-		quiet_settings = {}
-		for myroot, pkgsettings in self.pkgsettings.iteritems():
-			quiet_config = portage.config(clone=pkgsettings)
-			quiet_config["PORTAGE_QUIET"] = "1"
-			quiet_config.backup_changes("PORTAGE_QUIET")
-			quiet_settings[myroot] = quiet_config
-			del quiet_config
-
-		for x in self._mergelist:
-			if not isinstance(x, Package) or \
-				x.type_name != "ebuild":
-				continue
-
-			if not shown_verifying_msg:
-				shown_verifying_msg = True
-				self._status_msg("Verifying ebuild manifests")
-
-			root_config = x.root_config
-			portdb = root_config.trees["porttree"].dbapi
-			quiet_config = quiet_settings[root_config.root]
-			quiet_config["O"] = os.path.dirname(portdb.findname(x.cpv))
-			if not portage.digestcheck([], quiet_config, strict=True):
-				return 1
-
-		return os.EX_OK
-
-	def _add_prefetchers(self):
-
-		if not self._parallel_fetch:
-			return
-
-		if self._parallel_fetch:
-			self._status_msg("Starting parallel fetch")
-
-			prefetchers = self._prefetchers
-			getbinpkg = "--getbinpkg" in self.myopts
-
-			# In order to avoid "waiting for lock" messages
-			# at the beginning, which annoy users, never
-			# spawn a prefetcher for the first package.
-			for pkg in self._mergelist[1:]:
-				prefetcher = self._create_prefetcher(pkg)
-				if prefetcher is not None:
-					self._task_queues.fetch.add(prefetcher)
-					prefetchers[pkg] = prefetcher
-
-	def _create_prefetcher(self, pkg):
-		"""
-		@return: a prefetcher, or None if not applicable
-		"""
-		prefetcher = None
-
-		if not isinstance(pkg, Package):
-			pass
-
-		elif pkg.type_name == "ebuild":
-
-			prefetcher = EbuildFetcher(background=True,
-				config_pool=self._ConfigPool(pkg.root,
-				self._allocate_config, self._deallocate_config),
-				fetchonly=1, logfile=self._fetch_log,
-				pkg=pkg, prefetch=True, scheduler=self._sched_iface)
-
-		elif pkg.type_name == "binary" and \
-			"--getbinpkg" in self.myopts and \
-			pkg.root_config.trees["bintree"].isremote(pkg.cpv):
-
-			prefetcher = BinpkgPrefetcher(background=True,
-				pkg=pkg, scheduler=self._sched_iface)
-
-		return prefetcher
-
-	def _is_restart_scheduled(self):
-		"""
-		Check if the merge list contains a replacement
-		for the current running instance, that will result
-		in restart after merge.
-		@rtype: bool
-		@returns: True if a restart is scheduled, False otherwise.
-		"""
-		if self._opts_no_restart.intersection(self.myopts):
-			return False
-
-		mergelist = self._mergelist
-
-		for i, pkg in enumerate(mergelist):
-			if self._is_restart_necessary(pkg) and \
-				i != len(mergelist) - 1:
-				return True
-
-		return False
-
-	def _is_restart_necessary(self, pkg):
-		"""
-		@return: True if merging the given package
-			requires restart, False otherwise.
-		"""
-
-		# Figure out if we need a restart.
-		if pkg.root == self._running_root.root and \
-			portage.match_from_list(
-			portage.const.PORTAGE_PACKAGE_ATOM, [pkg]):
-			if self._running_portage:
-				return pkg.cpv != self._running_portage.cpv
-			return True
-		return False
-
-	def _restart_if_necessary(self, pkg):
-		"""
-		Use execv() to restart emerge. This happens
-		if portage upgrades itself and there are
-		remaining packages in the list.
-		"""
-
-		if self._opts_no_restart.intersection(self.myopts):
-			return
-
-		if not self._is_restart_necessary(pkg):
-			return
-
-		if pkg == self._mergelist[-1]:
-			return
-
-		self._main_loop_cleanup()
-
-		logger = self._logger
-		pkg_count = self._pkg_count
-		mtimedb = self._mtimedb
-		bad_resume_opts = self._bad_resume_opts
-
-		logger.log(" ::: completed emerge (%s of %s) %s to %s" % \
-			(pkg_count.curval, pkg_count.maxval, pkg.cpv, pkg.root))
-
-		logger.log(" *** RESTARTING " + \
-			"emerge via exec() after change of " + \
-			"portage version.")
-
-		mtimedb["resume"]["mergelist"].remove(list(pkg))
-		mtimedb.commit()
-		portage.run_exitfuncs()
-		mynewargv = [sys.argv[0], "--resume"]
-		resume_opts = self.myopts.copy()
-		# For automatic resume, we need to prevent
-		# any of bad_resume_opts from leaking in
-		# via EMERGE_DEFAULT_OPTS.
-		resume_opts["--ignore-default-opts"] = True
-		for myopt, myarg in resume_opts.iteritems():
-			if myopt not in bad_resume_opts:
-				if myarg is True:
-					mynewargv.append(myopt)
-				else:
-					mynewargv.append(myopt +"="+ str(myarg))
-		# priority only needs to be adjusted on the first run
-		os.environ["PORTAGE_NICENESS"] = "0"
-		os.execv(mynewargv[0], mynewargv)
-
-	def merge(self):
-
-		if "--resume" in self.myopts:
-			# We're resuming.
-			portage.writemsg_stdout(
-				colorize("GOOD", "*** Resuming merge...\n"), noiselevel=-1)
-			self._logger.log(" *** Resuming merge...")
-
-		self._save_resume_list()
-
-		try:
-			self._background = self._background_mode()
-		except self._unknown_internal_error:
-			return 1
-
-		for root in self.trees:
-			root_config = self.trees[root]["root_config"]
-
-			# Even for --pretend --fetch mode, PORTAGE_TMPDIR is required
-			# since it might spawn pkg_nofetch which requires PORTAGE_BUILDDIR
-			# for ensuring sane $PWD (bug #239560) and storing elog messages.
-			tmpdir = root_config.settings.get("PORTAGE_TMPDIR", "")
-			if not tmpdir or not os.path.isdir(tmpdir):
-				msg = "The directory specified in your " + \
-					"PORTAGE_TMPDIR variable, '%s', " % tmpdir + \
-				"does not exist. Please create this " + \
-				"directory or correct your PORTAGE_TMPDIR setting."
-				msg = textwrap.wrap(msg, 70)
-				out = portage.output.EOutput()
-				for l in msg:
-					out.eerror(l)
-				return 1
-
-			if self._background:
-				root_config.settings.unlock()
-				root_config.settings["PORTAGE_BACKGROUND"] = "1"
-				root_config.settings.backup_changes("PORTAGE_BACKGROUND")
-				root_config.settings.lock()
-
-			self.pkgsettings[root] = portage.config(
-				clone=root_config.settings)
-
-		rval = self._generate_digests()
-		if rval != os.EX_OK:
-			return rval
-
-		rval = self._check_manifests()
-		if rval != os.EX_OK:
-			return rval
-
-		keep_going = "--keep-going" in self.myopts
-		fetchonly = self._build_opts.fetchonly
-		mtimedb = self._mtimedb
-		failed_pkgs = self._failed_pkgs
-
-		while True:
-			rval = self._merge()
-			if rval == os.EX_OK or fetchonly or not keep_going:
-				break
-			if "resume" not in mtimedb:
-				break
-			mergelist = self._mtimedb["resume"].get("mergelist")
-			if not mergelist:
-				break
-
-			if not failed_pkgs:
-				break
-
-			for failed_pkg in failed_pkgs:
-				mergelist.remove(list(failed_pkg.pkg))
-
-			self._failed_pkgs_all.extend(failed_pkgs)
-			del failed_pkgs[:]
-
-			if not mergelist:
-				break
-
-			if not self._calc_resume_list():
-				break
-
-			clear_caches(self.trees)
-			if not self._mergelist:
-				break
-
-			self._save_resume_list()
-			self._pkg_count.curval = 0
-			self._pkg_count.maxval = len([x for x in self._mergelist \
-				if isinstance(x, Package) and x.operation == "merge"])
-			self._status_display.maxval = self._pkg_count.maxval
-
-		self._logger.log(" *** Finished. Cleaning up...")
-
-		if failed_pkgs:
-			self._failed_pkgs_all.extend(failed_pkgs)
-			del failed_pkgs[:]
-
-		background = self._background
-		failure_log_shown = False
-		if background and len(self._failed_pkgs_all) == 1:
-			# If only one package failed then just show it's
-			# whole log for easy viewing.
-			failed_pkg = self._failed_pkgs_all[-1]
-			build_dir = failed_pkg.build_dir
-			log_file = None
-
-			log_paths = [failed_pkg.build_log]
-
-			log_path = self._locate_failure_log(failed_pkg)
-			if log_path is not None:
-				try:
-					log_file = open(log_path)
-				except IOError:
-					pass
-
-			if log_file is not None:
-				try:
-					for line in log_file:
-						writemsg_level(line, noiselevel=-1)
-				finally:
-					log_file.close()
-				failure_log_shown = True
-
-		# Dump mod_echo output now since it tends to flood the terminal.
-		# This allows us to avoid having more important output, generated
-		# later, from being swept away by the mod_echo output.
-		mod_echo_output =  _flush_elog_mod_echo()
-
-		if background and not failure_log_shown and \
-			self._failed_pkgs_all and \
-			self._failed_pkgs_die_msgs and \
-			not mod_echo_output:
-
-			printer = portage.output.EOutput()
-			for mysettings, key, logentries in self._failed_pkgs_die_msgs:
-				root_msg = ""
-				if mysettings["ROOT"] != "/":
-					root_msg = " merged to %s" % mysettings["ROOT"]
-				print
-				printer.einfo("Error messages for package %s%s:" % \
-					(colorize("INFORM", key), root_msg))
-				print
-				for phase in portage.const.EBUILD_PHASES:
-					if phase not in logentries:
-						continue
-					for msgtype, msgcontent in logentries[phase]:
-						if isinstance(msgcontent, basestring):
-							msgcontent = [msgcontent]
-						for line in msgcontent:
-							printer.eerror(line.strip("\n"))
-
-		if self._post_mod_echo_msgs:
-			for msg in self._post_mod_echo_msgs:
-				msg()
-
-		if len(self._failed_pkgs_all) > 1 or \
-			(self._failed_pkgs_all and "--keep-going" in self.myopts):
-			if len(self._failed_pkgs_all) > 1:
-				msg = "The following %d packages have " % \
-					len(self._failed_pkgs_all) + \
-					"failed to build or install:"
-			else:
-				msg = "The following package has " + \
-					"failed to build or install:"
-			prefix = bad(" * ")
-			writemsg(prefix + "\n", noiselevel=-1)
-			from textwrap import wrap
-			for line in wrap(msg, 72):
-				writemsg("%s%s\n" % (prefix, line), noiselevel=-1)
-			writemsg(prefix + "\n", noiselevel=-1)
-			for failed_pkg in self._failed_pkgs_all:
-				writemsg("%s\t%s\n" % (prefix,
-					colorize("INFORM", str(failed_pkg.pkg))),
-					noiselevel=-1)
-			writemsg(prefix + "\n", noiselevel=-1)
-
-		return rval
-
-	def _elog_listener(self, mysettings, key, logentries, fulltext):
-		errors = portage.elog.filter_loglevels(logentries, ["ERROR"])
-		if errors:
-			self._failed_pkgs_die_msgs.append(
-				(mysettings, key, errors))
-
-	def _locate_failure_log(self, failed_pkg):
-
-		build_dir = failed_pkg.build_dir
-		log_file = None
-
-		log_paths = [failed_pkg.build_log]
-
-		for log_path in log_paths:
-			if not log_path:
-				continue
-
-			try:
-				log_size = os.stat(log_path).st_size
-			except OSError:
-				continue
-
-			if log_size == 0:
-				continue
-
-			return log_path
-
-		return None
-
-	def _add_packages(self):
-		pkg_queue = self._pkg_queue
-		for pkg in self._mergelist:
-			if isinstance(pkg, Package):
-				pkg_queue.append(pkg)
-			elif isinstance(pkg, Blocker):
-				pass
-
-	def _system_merge_started(self, merge):
-		"""
-		Add any unsatisfied runtime deps to self._unsatisfied_system_deps.
-		"""
-		graph = self._digraph
-		if graph is None:
-			return
-		pkg = merge.merge.pkg
-
-		# Skip this if $ROOT != / since it shouldn't matter if there
-		# are unsatisfied system runtime deps in this case.
-		if pkg.root != '/':
-			return
-
-		completed_tasks = self._completed_tasks
-		unsatisfied = self._unsatisfied_system_deps
-
-		def ignore_non_runtime_or_satisfied(priority):
-			"""
-			Ignore non-runtime and satisfied runtime priorities.
-			"""
-			if isinstance(priority, DepPriority) and \
-				not priority.satisfied and \
-				(priority.runtime or priority.runtime_post):
-				return False
-			return True
-
-		# When checking for unsatisfied runtime deps, only check
-		# direct deps since indirect deps are checked when the
-		# corresponding parent is merged.
-		for child in graph.child_nodes(pkg,
-			ignore_priority=ignore_non_runtime_or_satisfied):
-			if not isinstance(child, Package) or \
-				child.operation == 'uninstall':
-				continue
-			if child is pkg:
-				continue
-			if child.operation == 'merge' and \
-				child not in completed_tasks:
-				unsatisfied.add(child)
-
-	def _merge_wait_exit_handler(self, task):
-		self._merge_wait_scheduled.remove(task)
-		self._merge_exit(task)
-
-	def _merge_exit(self, merge):
-		self._do_merge_exit(merge)
-		self._deallocate_config(merge.merge.settings)
-		if merge.returncode == os.EX_OK and \
-			not merge.merge.pkg.installed:
-			self._status_display.curval += 1
-		self._status_display.merges = len(self._task_queues.merge)
-		self._schedule()
-
-	def _do_merge_exit(self, merge):
-		pkg = merge.merge.pkg
-		if merge.returncode != os.EX_OK:
-			settings = merge.merge.settings
-			build_dir = settings.get("PORTAGE_BUILDDIR")
-			build_log = settings.get("PORTAGE_LOG_FILE")
-
-			self._failed_pkgs.append(self._failed_pkg(
-				build_dir=build_dir, build_log=build_log,
-				pkg=pkg,
-				returncode=merge.returncode))
-			self._failed_pkg_msg(self._failed_pkgs[-1], "install", "to")
-
-			self._status_display.failed = len(self._failed_pkgs)
-			return
-
-		self._task_complete(pkg)
-		pkg_to_replace = merge.merge.pkg_to_replace
-		if pkg_to_replace is not None:
-			# When a package is replaced, mark it's uninstall
-			# task complete (if any).
-			uninst_hash_key = \
-				("installed", pkg.root, pkg_to_replace.cpv, "uninstall")
-			self._task_complete(uninst_hash_key)
-
-		if pkg.installed:
-			return
-
-		self._restart_if_necessary(pkg)
-
-		# Call mtimedb.commit() after each merge so that
-		# --resume still works after being interrupted
-		# by reboot, sigkill or similar.
-		mtimedb = self._mtimedb
-		mtimedb["resume"]["mergelist"].remove(list(pkg))
-		if not mtimedb["resume"]["mergelist"]:
-			del mtimedb["resume"]
-		mtimedb.commit()
-
-	def _build_exit(self, build):
-		if build.returncode == os.EX_OK:
-			self.curval += 1
-			merge = PackageMerge(merge=build)
-			if not build.build_opts.buildpkgonly and \
-				build.pkg in self._deep_system_deps:
-				# Since dependencies on system packages are frequently
-				# unspecified, merge them only when no builds are executing.
-				self._merge_wait_queue.append(merge)
-				merge.addStartListener(self._system_merge_started)
-			else:
-				merge.addExitListener(self._merge_exit)
-				self._task_queues.merge.add(merge)
-				self._status_display.merges = len(self._task_queues.merge)
-		else:
-			settings = build.settings
-			build_dir = settings.get("PORTAGE_BUILDDIR")
-			build_log = settings.get("PORTAGE_LOG_FILE")
-
-			self._failed_pkgs.append(self._failed_pkg(
-				build_dir=build_dir, build_log=build_log,
-				pkg=build.pkg,
-				returncode=build.returncode))
-			self._failed_pkg_msg(self._failed_pkgs[-1], "emerge", "for")
-
-			self._status_display.failed = len(self._failed_pkgs)
-			self._deallocate_config(build.settings)
-		self._jobs -= 1
-		self._status_display.running = self._jobs
-		self._schedule()
-
-	def _extract_exit(self, build):
-		self._build_exit(build)
-
-	def _task_complete(self, pkg):
-		self._completed_tasks.add(pkg)
-		self._unsatisfied_system_deps.discard(pkg)
-		self._choose_pkg_return_early = False
-
-	def _merge(self):
-
-		self._add_prefetchers()
-		self._add_packages()
-		pkg_queue = self._pkg_queue
-		failed_pkgs = self._failed_pkgs
-		portage.locks._quiet = self._background
-		portage.elog._emerge_elog_listener = self._elog_listener
-		rval = os.EX_OK
-
-		try:
-			self._main_loop()
-		finally:
-			self._main_loop_cleanup()
-			portage.locks._quiet = False
-			portage.elog._emerge_elog_listener = None
-			if failed_pkgs:
-				rval = failed_pkgs[-1].returncode
-
-		return rval
-
-	def _main_loop_cleanup(self):
-		del self._pkg_queue[:]
-		self._completed_tasks.clear()
-		self._deep_system_deps.clear()
-		self._unsatisfied_system_deps.clear()
-		self._choose_pkg_return_early = False
-		self._status_display.reset()
-		self._digraph = None
-		self._task_queues.fetch.clear()
-
-	def _choose_pkg(self):
-		"""
-		Choose a task that has all it's dependencies satisfied.
-		"""
-
-		if self._choose_pkg_return_early:
-			return None
-
-		if self._digraph is None:
-			if (self._jobs or self._task_queues.merge) and \
-				not ("--nodeps" in self.myopts and \
-				(self._max_jobs is True or self._max_jobs > 1)):
-				self._choose_pkg_return_early = True
-				return None
-			return self._pkg_queue.pop(0)
-
-		if not (self._jobs or self._task_queues.merge):
-			return self._pkg_queue.pop(0)
-
-		self._prune_digraph()
-
-		chosen_pkg = None
-		later = set(self._pkg_queue)
-		for pkg in self._pkg_queue:
-			later.remove(pkg)
-			if not self._dependent_on_scheduled_merges(pkg, later):
-				chosen_pkg = pkg
-				break
-
-		if chosen_pkg is not None:
-			self._pkg_queue.remove(chosen_pkg)
-
-		if chosen_pkg is None:
-			# There's no point in searching for a package to
-			# choose until at least one of the existing jobs
-			# completes.
-			self._choose_pkg_return_early = True
-
-		return chosen_pkg
-
-	def _dependent_on_scheduled_merges(self, pkg, later):
-		"""
-		Traverse the subgraph of the given packages deep dependencies
-		to see if it contains any scheduled merges.
-		@param pkg: a package to check dependencies for
-		@type pkg: Package
-		@param later: packages for which dependence should be ignored
-			since they will be merged later than pkg anyway and therefore
-			delaying the merge of pkg will not result in a more optimal
-			merge order
-		@type later: set
-		@rtype: bool
-		@returns: True if the package is dependent, False otherwise.
-		"""
-
-		graph = self._digraph
-		completed_tasks = self._completed_tasks
-
-		dependent = False
-		traversed_nodes = set([pkg])
-		direct_deps = graph.child_nodes(pkg)
-		node_stack = direct_deps
-		direct_deps = frozenset(direct_deps)
-		while node_stack:
-			node = node_stack.pop()
-			if node in traversed_nodes:
-				continue
-			traversed_nodes.add(node)
-			if not ((node.installed and node.operation == "nomerge") or \
-				(node.operation == "uninstall" and \
-				node not in direct_deps) or \
-				node in completed_tasks or \
-				node in later):
-				dependent = True
-				break
-			node_stack.extend(graph.child_nodes(node))
-
-		return dependent
-
-	def _allocate_config(self, root):
-		"""
-		Allocate a unique config instance for a task in order
-		to prevent interference between parallel tasks.
-		"""
-		if self._config_pool[root]:
-			temp_settings = self._config_pool[root].pop()
-		else:
-			temp_settings = portage.config(clone=self.pkgsettings[root])
-		# Since config.setcpv() isn't guaranteed to call config.reset() due to
-		# performance reasons, call it here to make sure all settings from the
-		# previous package get flushed out (such as PORTAGE_LOG_FILE).
-		temp_settings.reload()
-		temp_settings.reset()
-		return temp_settings
-
-	def _deallocate_config(self, settings):
-		self._config_pool[settings["ROOT"]].append(settings)
-
-	def _main_loop(self):
-
-		# Only allow 1 job max if a restart is scheduled
-		# due to portage update.
-		if self._is_restart_scheduled() or \
-			self._opts_no_background.intersection(self.myopts):
-			self._set_max_jobs(1)
-
-		merge_queue = self._task_queues.merge
-
-		while self._schedule():
-			if self._poll_event_handlers:
-				self._poll_loop()
-
-		while True:
-			self._schedule()
-			if not (self._jobs or merge_queue):
-				break
-			if self._poll_event_handlers:
-				self._poll_loop()
-
-	def _keep_scheduling(self):
-		return bool(self._pkg_queue and \
-			not (self._failed_pkgs and not self._build_opts.fetchonly))
-
-	def _schedule_tasks(self):
-
-		# When the number of jobs drops to zero, process all waiting merges.
-		if not self._jobs and self._merge_wait_queue:
-			for task in self._merge_wait_queue:
-				task.addExitListener(self._merge_wait_exit_handler)
-				self._task_queues.merge.add(task)
-			self._status_display.merges = len(self._task_queues.merge)
-			self._merge_wait_scheduled.extend(self._merge_wait_queue)
-			del self._merge_wait_queue[:]
-
-		self._schedule_tasks_imp()
-		self._status_display.display()
-
-		state_change = 0
-		for q in self._task_queues.values():
-			if q.schedule():
-				state_change += 1
-
-		# Cancel prefetchers if they're the only reason
-		# the main poll loop is still running.
-		if self._failed_pkgs and not self._build_opts.fetchonly and \
-			not (self._jobs or self._task_queues.merge) and \
-			self._task_queues.fetch:
-			self._task_queues.fetch.clear()
-			state_change += 1
-
-		if state_change:
-			self._schedule_tasks_imp()
-			self._status_display.display()
-
-		return self._keep_scheduling()
-
-	def _job_delay(self):
-		"""
-		@rtype: bool
-		@returns: True if job scheduling should be delayed, False otherwise.
-		"""
-
-		if self._jobs and self._max_load is not None:
-
-			current_time = time.time()
-
-			delay = self._job_delay_factor * self._jobs ** self._job_delay_exp
-			if delay > self._job_delay_max:
-				delay = self._job_delay_max
-			if (current_time - self._previous_job_start_time) < delay:
-				return True
-
-		return False
-
-	def _schedule_tasks_imp(self):
-		"""
-		@rtype: bool
-		@returns: True if state changed, False otherwise.
-		"""
-
-		state_change = 0
-
-		while True:
-
-			if not self._keep_scheduling():
-				return bool(state_change)
-
-			if self._choose_pkg_return_early or \
-				self._merge_wait_scheduled or \
-				(self._jobs and self._unsatisfied_system_deps) or \
-				not self._can_add_job() or \
-				self._job_delay():
-				return bool(state_change)
-
-			pkg = self._choose_pkg()
-			if pkg is None:
-				return bool(state_change)
-
-			state_change += 1
-
-			if not pkg.installed:
-				self._pkg_count.curval += 1
-
-			task = self._task(pkg)
-
-			if pkg.installed:
-				merge = PackageMerge(merge=task)
-				merge.addExitListener(self._merge_exit)
-				self._task_queues.merge.add(merge)
-
-			elif pkg.built:
-				self._jobs += 1
-				self._previous_job_start_time = time.time()
-				self._status_display.running = self._jobs
-				task.addExitListener(self._extract_exit)
-				self._task_queues.jobs.add(task)
-
-			else:
-				self._jobs += 1
-				self._previous_job_start_time = time.time()
-				self._status_display.running = self._jobs
-				task.addExitListener(self._build_exit)
-				self._task_queues.jobs.add(task)
-
-		return bool(state_change)
-
-	def _task(self, pkg):
-
-		pkg_to_replace = None
-		if pkg.operation != "uninstall":
-			vardb = pkg.root_config.trees["vartree"].dbapi
-			previous_cpv = vardb.match(pkg.slot_atom)
-			if previous_cpv:
-				previous_cpv = previous_cpv.pop()
-				pkg_to_replace = self._pkg(previous_cpv,
-					"installed", pkg.root_config, installed=True)
-
-		task = MergeListItem(args_set=self._args_set,
-			background=self._background, binpkg_opts=self._binpkg_opts,
-			build_opts=self._build_opts,
-			config_pool=self._ConfigPool(pkg.root,
-			self._allocate_config, self._deallocate_config),
-			emerge_opts=self.myopts,
-			find_blockers=self._find_blockers(pkg), logger=self._logger,
-			mtimedb=self._mtimedb, pkg=pkg, pkg_count=self._pkg_count.copy(),
-			pkg_to_replace=pkg_to_replace,
-			prefetcher=self._prefetchers.get(pkg),
-			scheduler=self._sched_iface,
-			settings=self._allocate_config(pkg.root),
-			statusMessage=self._status_msg,
-			world_atom=self._world_atom)
-
-		return task
-
-	def _failed_pkg_msg(self, failed_pkg, action, preposition):
-		pkg = failed_pkg.pkg
-		msg = "%s to %s %s" % \
-			(bad("Failed"), action, colorize("INFORM", pkg.cpv))
-		if pkg.root != "/":
-			msg += " %s %s" % (preposition, pkg.root)
-
-		log_path = self._locate_failure_log(failed_pkg)
-		if log_path is not None:
-			msg += ", Log file:"
-		self._status_msg(msg)
-
-		if log_path is not None:
-			self._status_msg(" '%s'" % (colorize("INFORM", log_path),))
-
-	def _status_msg(self, msg):
-		"""
-		Display a brief status message (no newlines) in the status display.
-		This is called by tasks to provide feedback to the user. This
-		delegates the resposibility of generating \r and \n control characters,
-		to guarantee that lines are created or erased when necessary and
-		appropriate.
-
-		@type msg: str
-		@param msg: a brief status message (no newlines allowed)
-		"""
-		if not self._background:
-			writemsg_level("\n")
-		self._status_display.displayMessage(msg)
-
-	def _save_resume_list(self):
-		"""
-		Do this before verifying the ebuild Manifests since it might
-		be possible for the user to use --resume --skipfirst get past
-		a non-essential package with a broken digest.
-		"""
-		mtimedb = self._mtimedb
-		mtimedb["resume"]["mergelist"] = [list(x) \
-			for x in self._mergelist \
-			if isinstance(x, Package) and x.operation == "merge"]
-
-		mtimedb.commit()
-
-	def _calc_resume_list(self):
-		"""
-		Use the current resume list to calculate a new one,
-		dropping any packages with unsatisfied deps.
-		@rtype: bool
-		@returns: True if successful, False otherwise.
-		"""
-		print colorize("GOOD", "*** Resuming merge...")
-
-		if self._show_list():
-			if "--tree" in self.myopts:
-				portage.writemsg_stdout("\n" + \
-					darkgreen("These are the packages that " + \
-					"would be merged, in reverse order:\n\n"))
-
-			else:
-				portage.writemsg_stdout("\n" + \
-					darkgreen("These are the packages that " + \
-					"would be merged, in order:\n\n"))
-
-		show_spinner = "--quiet" not in self.myopts and \
-			"--nodeps" not in self.myopts
-
-		if show_spinner:
-			print "Calculating dependencies  ",
-
-		myparams = create_depgraph_params(self.myopts, None)
-		success = False
-		e = None
-		try:
-			success, mydepgraph, dropped_tasks = resume_depgraph(
-				self.settings, self.trees, self._mtimedb, self.myopts,
-				myparams, self._spinner)
-		except depgraph.UnsatisfiedResumeDep, exc:
-			# rename variable to avoid python-3.0 error:
-			# SyntaxError: can not delete variable 'e' referenced in nested
-			#              scope
-			e = exc
-			mydepgraph = e.depgraph
-			dropped_tasks = set()
-
-		if show_spinner:
-			print "\b\b... done!"
-
-		if e is not None:
-			def unsatisfied_resume_dep_msg():
-				mydepgraph.display_problems()
-				out = portage.output.EOutput()
-				out.eerror("One or more packages are either masked or " + \
-					"have missing dependencies:")
-				out.eerror("")
-				indent = "  "
-				show_parents = set()
-				for dep in e.value:
-					if dep.parent in show_parents:
-						continue
-					show_parents.add(dep.parent)
-					if dep.atom is None:
-						out.eerror(indent + "Masked package:")
-						out.eerror(2 * indent + str(dep.parent))
-						out.eerror("")
-					else:
-						out.eerror(indent + str(dep.atom) + " pulled in by:")
-						out.eerror(2 * indent + str(dep.parent))
-						out.eerror("")
-				msg = "The resume list contains packages " + \
-					"that are either masked or have " + \
-					"unsatisfied dependencies. " + \
-					"Please restart/continue " + \
-					"the operation manually, or use --skipfirst " + \
-					"to skip the first package in the list and " + \
-					"any other packages that may be " + \
-					"masked or have missing dependencies."
-				for line in textwrap.wrap(msg, 72):
-					out.eerror(line)
-			self._post_mod_echo_msgs.append(unsatisfied_resume_dep_msg)
-			return False
-
-		if success and self._show_list():
-			mylist = mydepgraph.altlist()
-			if mylist:
-				if "--tree" in self.myopts:
-					mylist.reverse()
-				mydepgraph.display(mylist, favorites=self._favorites)
-
-		if not success:
-			self._post_mod_echo_msgs.append(mydepgraph.display_problems)
-			return False
-		mydepgraph.display_problems()
-
-		mylist = mydepgraph.altlist()
-		mydepgraph.break_refs(mylist)
-		mydepgraph.break_refs(dropped_tasks)
-		self._mergelist = mylist
-		self._set_digraph(mydepgraph.schedulerGraph())
-
-		msg_width = 75
-		for task in dropped_tasks:
-			if not (isinstance(task, Package) and task.operation == "merge"):
-				continue
-			pkg = task
-			msg = "emerge --keep-going:" + \
-				" %s" % (pkg.cpv,)
-			if pkg.root != "/":
-				msg += " for %s" % (pkg.root,)
-			msg += " dropped due to unsatisfied dependency."
-			for line in textwrap.wrap(msg, msg_width):
-				eerror(line, phase="other", key=pkg.cpv)
-			settings = self.pkgsettings[pkg.root]
-			# Ensure that log collection from $T is disabled inside
-			# elog_process(), since any logs that might exist are
-			# not valid here.
-			settings.pop("T", None)
-			portage.elog.elog_process(pkg.cpv, settings)
-			self._failed_pkgs_all.append(self._failed_pkg(pkg=pkg))
-
-		return True
-
-	def _show_list(self):
-		myopts = self.myopts
-		if "--quiet" not in myopts and \
-			("--ask" in myopts or "--tree" in myopts or \
-			"--verbose" in myopts):
-			return True
-		return False
-
-	def _world_atom(self, pkg):
-		"""
-		Add the package to the world file, but only if
-		it's supposed to be added. Otherwise, do nothing.
-		"""
-
-		if set(("--buildpkgonly", "--fetchonly",
-			"--fetch-all-uri",
-			"--oneshot", "--onlydeps",
-			"--pretend")).intersection(self.myopts):
-			return
-
-		if pkg.root != self.target_root:
-			return
-
-		args_set = self._args_set
-		if not args_set.findAtomForPackage(pkg):
-			return
-
-		logger = self._logger
-		pkg_count = self._pkg_count
-		root_config = pkg.root_config
-		world_set = root_config.sets["world"]
-		world_locked = False
-		if hasattr(world_set, "lock"):
-			world_set.lock()
-			world_locked = True
-
-		try:
-			if hasattr(world_set, "load"):
-				world_set.load() # maybe it's changed on disk
-
-			atom = create_world_atom(pkg, args_set, root_config)
-			if atom:
-				if hasattr(world_set, "add"):
-					self._status_msg(('Recording %s in "world" ' + \
-						'favorites file...') % atom)
-					logger.log(" === (%s of %s) Updating world file (%s)" % \
-						(pkg_count.curval, pkg_count.maxval, pkg.cpv))
-					world_set.add(atom)
-				else:
-					writemsg_level('\n!!! Unable to record %s in "world"\n' % \
-						(atom,), level=logging.WARN, noiselevel=-1)
-		finally:
-			if world_locked:
-				world_set.unlock()
-
-	def _pkg(self, cpv, type_name, root_config, installed=False):
-		"""
-		Get a package instance from the cache, or create a new
-		one if necessary. Raises KeyError from aux_get if it
-		failures for some reason (package does not exist or is
-		corrupt).
-		"""
-		operation = "merge"
-		if installed:
-			operation = "nomerge"
-
-		if self._digraph is not None:
-			# Reuse existing instance when available.
-			pkg = self._digraph.get(
-				(type_name, root_config.root, cpv, operation))
-			if pkg is not None:
-				return pkg
-
-		tree_type = depgraph.pkg_tree_map[type_name]
-		db = root_config.trees[tree_type].dbapi
-		db_keys = list(self.trees[root_config.root][
-			tree_type].dbapi._aux_cache_keys)
-		metadata = izip(db_keys, db.aux_get(cpv, db_keys))
-		pkg = Package(cpv=cpv, metadata=metadata,
-			root_config=root_config, installed=installed)
-		if type_name == "ebuild":
-			settings = self.pkgsettings[root_config.root]
-			settings.setcpv(pkg)
-			pkg.metadata["USE"] = settings["PORTAGE_USE"]
-			pkg.metadata['CHOST'] = settings.get('CHOST', '')
-
-		return pkg
-
 def chk_updated_info_files(root, infodirs, prev_mtimes, retval):
 
 	if os.path.exists("/usr/bin/install-info"):
@@ -6958,23 +395,6 @@ def display_preserved_libs(vardbapi):
 		print "Use " + colorize("GOOD", "emerge @preserved-rebuild") + " to rebuild packages using these libraries"
 
 
-def _flush_elog_mod_echo():
-	"""
-	Dump the mod_echo output now so that our other
-	notifications are shown last.
-	@rtype: bool
-	@returns: True if messages were shown, False otherwise.
-	"""
-	messages_shown = False
-	try:
-		from portage.elog import mod_echo
-	except ImportError:
-		pass # happens during downgrade to a version without the module
-	else:
-		messages_shown = bool(mod_echo._items)
-		mod_echo.finalize()
-	return messages_shown
-
 def post_emerge(root_config, myopts, mtimedb, retval):
 	"""
 	Misc. things to run at the end of a merge session.
@@ -7134,34 +554,6 @@ def checkUpdatedNewsItems(portdb, vardb, NEWS_PATH, UNREAD_PATH, repo_id,
 	manager = NewsManager(portdb, vardb, NEWS_PATH, UNREAD_PATH)
 	return manager.getUnreadItems( repo_id, update=update )
 
-def insert_category_into_atom(atom, category):
-	alphanum = re.search(r'\w', atom)
-	if alphanum:
-		ret = atom[:alphanum.start()] + "%s/" % category + \
-			atom[alphanum.start():]
-	else:
-		ret = None
-	return ret
-
-def is_valid_package_atom(x):
-	if "/" not in x:
-		alphanum = re.search(r'\w', x)
-		if alphanum:
-			x = x[:alphanum.start()] + "cat/" + x[alphanum.start():]
-	return portage.isvalidatom(x)
-
-def show_blocker_docs_link():
-	print
-	print "For more information about " + bad("Blocked Packages") + ", please refer to the following"
-	print "section of the Gentoo Linux x86 Handbook (architecture is irrelevant):"
-	print
-	print "http://www.gentoo.org/doc/en/handbook/handbook-x86.xml?full=1#blocked"
-	print
-
-def show_mask_docs():
-	print "For more information, see the MASKED PACKAGES section in the emerge"
-	print "man page or refer to the Gentoo Handbook."
-
 def action_sync(settings, trees, mtimedb, myopts, myaction):
 	xterm_titles = "notitles" not in settings.features
 	emergelog(xterm_titles, " === sync")
@@ -9108,80 +2500,6 @@ def action_depclean(settings, trees, ldpath_mtimes,
 	else:
 		print "Number removed:       "+str(len(cleanlist))
 
-def resume_depgraph(settings, trees, mtimedb, myopts, myparams, spinner):
-	"""
-	Construct a depgraph for the given resume list. This will raise
-	PackageNotFound or depgraph.UnsatisfiedResumeDep when necessary.
-	@rtype: tuple
-	@returns: (success, depgraph, dropped_tasks)
-	"""
-	skip_masked = True
-	skip_unsatisfied = True
-	mergelist = mtimedb["resume"]["mergelist"]
-	dropped_tasks = set()
-	while True:
-		mydepgraph = depgraph(settings, trees,
-			myopts, myparams, spinner)
-		try:
-			success = mydepgraph.loadResumeCommand(mtimedb["resume"],
-				skip_masked=skip_masked)
-		except depgraph.UnsatisfiedResumeDep, e:
-			if not skip_unsatisfied:
-				raise
-
-			graph = mydepgraph.digraph
-			unsatisfied_parents = dict((dep.parent, dep.parent) \
-				for dep in e.value)
-			traversed_nodes = set()
-			unsatisfied_stack = list(unsatisfied_parents)
-			while unsatisfied_stack:
-				pkg = unsatisfied_stack.pop()
-				if pkg in traversed_nodes:
-					continue
-				traversed_nodes.add(pkg)
-
-				# If this package was pulled in by a parent
-				# package scheduled for merge, removing this
-				# package may cause the the parent package's
-				# dependency to become unsatisfied.
-				for parent_node in graph.parent_nodes(pkg):
-					if not isinstance(parent_node, Package) \
-						or parent_node.operation not in ("merge", "nomerge"):
-						continue
-					unsatisfied = \
-						graph.child_nodes(parent_node,
-						ignore_priority=DepPrioritySatisfiedRange.ignore_soft)
-					if pkg in unsatisfied:
-						unsatisfied_parents[parent_node] = parent_node
-						unsatisfied_stack.append(parent_node)
-
-			pruned_mergelist = []
-			for x in mergelist:
-				if isinstance(x, list) and \
-					tuple(x) not in unsatisfied_parents:
-					pruned_mergelist.append(x)
-
-			# If the mergelist doesn't shrink then this loop is infinite.
-			if len(pruned_mergelist) == len(mergelist):
-				# This happens if a package can't be dropped because
-				# it's already installed, but it has unsatisfied PDEPEND.
-				raise
-			mergelist[:] = pruned_mergelist
-
-			# Exclude installed packages that have been removed from the graph due
-			# to failure to build/install runtime dependencies after the dependent
-			# package has already been installed.
-			dropped_tasks.update(pkg for pkg in \
-				unsatisfied_parents if pkg.operation != "nomerge")
-			mydepgraph.break_refs(unsatisfied_parents)
-
-			del e, graph, traversed_nodes, \
-				unsatisfied_parents, unsatisfied_stack
-			continue
-		else:
-			break
-	return (success, mydepgraph, dropped_tasks)
-
 def action_build(settings, trees, mtimedb,
 	myopts, myaction, myfiles, spinner):
 
@@ -9847,16 +3165,6 @@ def validate_ebuild_environment(trees):
 		settings = trees[myroot]["vartree"].settings
 		settings.validate()
 
-def clear_caches(trees):
-	for d in trees.itervalues():
-		d["porttree"].dbapi.melt()
-		d["porttree"].dbapi._aux_cache.clear()
-		d["bintree"].dbapi._aux_cache.clear()
-		d["bintree"].dbapi._clear_cache()
-		d["vartree"].dbapi.linkmap._clear_cache()
-	portage.dircache.clear()
-	gc.collect()
-
 def load_emerge_config(trees=None):
 	kwargs = {}
 	for k, envvar in (("config_root", "PORTAGE_CONFIGROOT"), ("target_root", "ROOT")):
@@ -10255,28 +3563,6 @@ def config_protect_check(trees):
 				msg += " for '%s'" % root
 			writemsg_level(msg, level=logging.WARN, noiselevel=-1)
 
-def ambiguous_package_name(arg, atoms, root_config, spinner, myopts):
-
-	if "--quiet" in myopts:
-		print "!!! The short ebuild name \"%s\" is ambiguous. Please specify" % arg
-		print "!!! one of the following fully-qualified ebuild names instead:\n"
-		for cp in sorted(set(portage.dep_getkey(atom) for atom in atoms)):
-			print "    " + colorize("INFORM", cp)
-		return
-
-	s = search(root_config, spinner, "--searchdesc" in myopts,
-		"--quiet" not in myopts, "--usepkg" in myopts,
-		"--usepkgonly" in myopts)
-	null_cp = portage.dep_getkey(insert_category_into_atom(
-		arg, "null"))
-	cat, atom_pn = portage.catsplit(null_cp)
-	s.searchkey = atom_pn
-	for cp in sorted(set(portage.dep_getkey(atom) for atom in atoms)):
-		s.addCP(cp)
-	s.output()
-	print "!!! The short ebuild name \"%s\" is ambiguous. Please specify" % arg
-	print "!!! one of the above fully-qualified ebuild names instead.\n"
-
 def profile_check(trees, myaction, myopts):
 	if myaction in ("info", "sync"):
 		return os.EX_OK
diff --git a/pym/_emerge/_find_deep_system_runtime_deps.py b/pym/_emerge/_find_deep_system_runtime_deps.py
new file mode 100644
index 000000000..3249168f2
--- /dev/null
+++ b/pym/_emerge/_find_deep_system_runtime_deps.py
@@ -0,0 +1,35 @@
+from _emerge.DepPriority import DepPriority
+from _emerge.Package import Package
+
+def _find_deep_system_runtime_deps(graph):
+	deep_system_deps = set()
+	node_stack = []
+	for node in graph:
+		if not isinstance(node, Package) or \
+			node.operation == 'uninstall':
+			continue
+		if node.root_config.sets['system'].findAtomForPackage(node):
+			node_stack.append(node)
+
+	def ignore_priority(priority):
+		"""
+		Ignore non-runtime priorities.
+		"""
+		if isinstance(priority, DepPriority) and \
+			(priority.runtime or priority.runtime_post):
+			return False
+		return True
+
+	while node_stack:
+		node = node_stack.pop()
+		if node in deep_system_deps:
+			continue
+		deep_system_deps.add(node)
+		for child in graph.child_nodes(node, ignore_priority=ignore_priority):
+			if not isinstance(child, Package) or \
+				child.operation == 'uninstall':
+				continue
+			node_stack.append(child)
+
+	return deep_system_deps
+
diff --git a/pym/_emerge/_flush_elog_mod_echo.py b/pym/_emerge/_flush_elog_mod_echo.py
new file mode 100644
index 000000000..61eeb29f7
--- /dev/null
+++ b/pym/_emerge/_flush_elog_mod_echo.py
@@ -0,0 +1,17 @@
+def _flush_elog_mod_echo():
+	"""
+	Dump the mod_echo output now so that our other
+	notifications are shown last.
+	@rtype: bool
+	@returns: True if messages were shown, False otherwise.
+	"""
+	messages_shown = False
+	try:
+		from portage.elog import mod_echo
+	except ImportError:
+		pass # happens during downgrade to a version without the module
+	else:
+		messages_shown = bool(mod_echo._items)
+		mod_echo.finalize()
+	return messages_shown
+
diff --git a/pym/_emerge/clear_caches.py b/pym/_emerge/clear_caches.py
new file mode 100644
index 000000000..ce903ba08
--- /dev/null
+++ b/pym/_emerge/clear_caches.py
@@ -0,0 +1,19 @@
+import gc
+
+try:
+	import portage
+except ImportError:
+	from os import path as osp
+	import sys
+	sys.path.insert(0, osp.join(osp.dirname(osp.dirname(osp.realpath(__file__))), "pym"))
+	import portage
+
+def clear_caches(trees):
+	for d in trees.itervalues():
+		d["porttree"].dbapi.melt()
+		d["porttree"].dbapi._aux_cache.clear()
+		d["bintree"].dbapi._aux_cache.clear()
+		d["bintree"].dbapi._clear_cache()
+		d["vartree"].dbapi.linkmap._clear_cache()
+	portage.dircache.clear()
+	gc.collect()
diff --git a/pym/_emerge/create_depgraph_params.py b/pym/_emerge/create_depgraph_params.py
new file mode 100644
index 000000000..fab741be5
--- /dev/null
+++ b/pym/_emerge/create_depgraph_params.py
@@ -0,0 +1,33 @@
+def create_depgraph_params(myopts, myaction):
+	#configure emerge engine parameters
+	#
+	# self:      include _this_ package regardless of if it is merged.
+	# selective: exclude the package if it is merged
+	# recurse:   go into the dependencies
+	# deep:      go into the dependencies of already merged packages
+	# empty:     pretend nothing is merged
+	# complete:  completely account for all known dependencies
+	# remove:    build graph for use in removing packages
+	myparams = set(["recurse"])
+
+	if myaction == "remove":
+		myparams.add("remove")
+		myparams.add("complete")
+		return myparams
+
+	if "--update" in myopts or \
+		"--newuse" in myopts or \
+		"--reinstall" in myopts or \
+		"--noreplace" in myopts:
+		myparams.add("selective")
+	if "--emptytree" in myopts:
+		myparams.add("empty")
+		myparams.discard("selective")
+	if "--nodeps" in myopts:
+		myparams.discard("recurse")
+	if "--deep" in myopts:
+		myparams.add("deep")
+	if "--complete-graph" in myopts:
+		myparams.add("complete")
+	return myparams
+
diff --git a/pym/_emerge/create_world_atom.py b/pym/_emerge/create_world_atom.py
new file mode 100644
index 000000000..1b13c4058
--- /dev/null
+++ b/pym/_emerge/create_world_atom.py
@@ -0,0 +1,91 @@
+try:
+	import portage
+except ImportError:
+	from os import path as osp
+	import sys
+	sys.path.insert(0, osp.join(osp.dirname(osp.dirname(osp.realpath(__file__))), "pym"))
+	import portage
+
+def create_world_atom(pkg, args_set, root_config):
+	"""Create a new atom for the world file if one does not exist.  If the
+	argument atom is precise enough to identify a specific slot then a slot
+	atom will be returned. Atoms that are in the system set may also be stored
+	in world since system atoms can only match one slot while world atoms can
+	be greedy with respect to slots.  Unslotted system packages will not be
+	stored in world."""
+
+	arg_atom = args_set.findAtomForPackage(pkg)
+	if not arg_atom:
+		return None
+	cp = portage.dep_getkey(arg_atom)
+	new_world_atom = cp
+	sets = root_config.sets
+	portdb = root_config.trees["porttree"].dbapi
+	vardb = root_config.trees["vartree"].dbapi
+	available_slots = set(portdb.aux_get(cpv, ["SLOT"])[0] \
+		for cpv in portdb.match(cp))
+	slotted = len(available_slots) > 1 or \
+		(len(available_slots) == 1 and "0" not in available_slots)
+	if not slotted:
+		# check the vdb in case this is multislot
+		available_slots = set(vardb.aux_get(cpv, ["SLOT"])[0] \
+			for cpv in vardb.match(cp))
+		slotted = len(available_slots) > 1 or \
+			(len(available_slots) == 1 and "0" not in available_slots)
+	if slotted and arg_atom != cp:
+		# If the user gave a specific atom, store it as a
+		# slot atom in the world file.
+		slot_atom = pkg.slot_atom
+
+		# For USE=multislot, there are a couple of cases to
+		# handle here:
+		#
+		# 1) SLOT="0", but the real SLOT spontaneously changed to some
+		#    unknown value, so just record an unslotted atom.
+		#
+		# 2) SLOT comes from an installed package and there is no
+		#    matching SLOT in the portage tree.
+		#
+		# Make sure that the slot atom is available in either the
+		# portdb or the vardb, since otherwise the user certainly
+		# doesn't want the SLOT atom recorded in the world file
+		# (case 1 above).  If it's only available in the vardb,
+		# the user may be trying to prevent a USE=multislot
+		# package from being removed by --depclean (case 2 above).
+
+		mydb = portdb
+		if not portdb.match(slot_atom):
+			# SLOT seems to come from an installed multislot package
+			mydb = vardb
+		# If there is no installed package matching the SLOT atom,
+		# it probably changed SLOT spontaneously due to USE=multislot,
+		# so just record an unslotted atom.
+		if vardb.match(slot_atom):
+			# Now verify that the argument is precise
+			# enough to identify a specific slot.
+			matches = mydb.match(arg_atom)
+			matched_slots = set()
+			for cpv in matches:
+				matched_slots.add(mydb.aux_get(cpv, ["SLOT"])[0])
+			if len(matched_slots) == 1:
+				new_world_atom = slot_atom
+
+	if new_world_atom == sets["world"].findAtomForPackage(pkg):
+		# Both atoms would be identical, so there's nothing to add.
+		return None
+	if not slotted:
+		# Unlike world atoms, system atoms are not greedy for slots, so they
+		# can't be safely excluded from world if they are slotted.
+		system_atom = sets["system"].findAtomForPackage(pkg)
+		if system_atom:
+			if not portage.dep_getkey(system_atom).startswith("virtual/"):
+				return None
+			# System virtuals aren't safe to exclude from world since they can
+			# match multiple old-style virtuals but only one of them will be
+			# pulled in by update or depclean.
+			providers = portdb.mysettings.getvirtuals().get(
+				portage.dep_getkey(system_atom))
+			if providers and len(providers) == 1 and providers[0] == cp:
+				return None
+	return new_world_atom
+
diff --git a/pym/_emerge/depgraph.py b/pym/_emerge/depgraph.py
new file mode 100644
index 000000000..b5901285b
--- /dev/null
+++ b/pym/_emerge/depgraph.py
@@ -0,0 +1,4973 @@
+import gc
+import os
+import re
+import sys
+import textwrap
+from itertools import chain, izip
+
+try:
+	import portage
+except ImportError:
+	from os import path as osp
+	sys.path.insert(0, osp.join(osp.dirname(osp.dirname(osp.realpath(__file__))), "pym"))
+	import portage
+
+from portage import digraph
+from portage.output import bold, blue, colorize, create_color_func, darkblue, \
+	darkgreen, green, nc_len, red, teal, turquoise, yellow
+bad = create_color_func("BAD")
+from portage.sets import SETPREFIX
+from portage.sets.base import InternalPackageSet
+from portage.util import cmp_sort_key, writemsg
+
+from _emerge.AtomArg import AtomArg
+from _emerge.Blocker import Blocker
+from _emerge.BlockerCache import BlockerCache
+from _emerge.BlockerDepPriority import BlockerDepPriority
+from _emerge.countdown import countdown
+from _emerge.create_world_atom import create_world_atom
+from _emerge.Dependency import Dependency
+from _emerge.DependencyArg import DependencyArg
+from _emerge.DepPriority import DepPriority
+from _emerge.DepPriorityNormalRange import DepPriorityNormalRange
+from _emerge.DepPrioritySatisfiedRange import DepPrioritySatisfiedRange
+from _emerge.FakeVartree import FakeVartree
+from _emerge._find_deep_system_runtime_deps import _find_deep_system_runtime_deps
+from _emerge.format_size import format_size
+from _emerge.is_valid_package_atom import is_valid_package_atom
+from _emerge.Package import Package
+from _emerge.PackageArg import PackageArg
+from _emerge.PackageCounters import PackageCounters
+from _emerge.PackageVirtualDbapi import PackageVirtualDbapi
+from _emerge.RepoDisplay import RepoDisplay
+from _emerge.RootConfig import RootConfig
+from _emerge.search import search
+from _emerge.SetArg import SetArg
+from _emerge.show_invalid_depstring_notice import show_invalid_depstring_notice
+from _emerge.UnmergeDepPriority import UnmergeDepPriority
+from _emerge.visible import visible
+
+import portage.proxy.lazyimport
+import portage.proxy as proxy
+proxy.lazyimport.lazyimport(globals(),
+	'_emerge.Scheduler:Scheduler',
+)
+#from _emerge.Scheduler import Scheduler
+class depgraph(object):
+
+	pkg_tree_map = RootConfig.pkg_tree_map
+
+	_dep_keys = ["DEPEND", "RDEPEND", "PDEPEND"]
+
+	def __init__(self, settings, trees, myopts, myparams, spinner):
+		self.settings = settings
+		self.target_root = settings["ROOT"]
+		self.myopts = myopts
+		self.myparams = myparams
+		self.edebug = 0
+		if settings.get("PORTAGE_DEBUG", "") == "1":
+			self.edebug = 1
+		self.spinner = spinner
+		self._running_root = trees["/"]["root_config"]
+		self._opts_no_restart = Scheduler._opts_no_restart
+		self.pkgsettings = {}
+		# Maps slot atom to package for each Package added to the graph.
+		self._slot_pkg_map = {}
+		# Maps nodes to the reasons they were selected for reinstallation.
+		self._reinstall_nodes = {}
+		self.mydbapi = {}
+		self.trees = {}
+		self._trees_orig = trees
+		self.roots = {}
+		# Contains a filtered view of preferred packages that are selected
+		# from available repositories.
+		self._filtered_trees = {}
+		# Contains installed packages and new packages that have been added
+		# to the graph.
+		self._graph_trees = {}
+		# All Package instances
+		self._pkg_cache = {}
+		for myroot in trees:
+			self.trees[myroot] = {}
+			# Create a RootConfig instance that references
+			# the FakeVartree instead of the real one.
+			self.roots[myroot] = RootConfig(
+				trees[myroot]["vartree"].settings,
+				self.trees[myroot],
+				trees[myroot]["root_config"].setconfig)
+			for tree in ("porttree", "bintree"):
+				self.trees[myroot][tree] = trees[myroot][tree]
+			self.trees[myroot]["vartree"] = \
+				FakeVartree(trees[myroot]["root_config"],
+					pkg_cache=self._pkg_cache)
+			self.pkgsettings[myroot] = portage.config(
+				clone=self.trees[myroot]["vartree"].settings)
+			self._slot_pkg_map[myroot] = {}
+			vardb = self.trees[myroot]["vartree"].dbapi
+			preload_installed_pkgs = "--nodeps" not in self.myopts and \
+				"--buildpkgonly" not in self.myopts
+			# This fakedbapi instance will model the state that the vdb will
+			# have after new packages have been installed.
+			fakedb = PackageVirtualDbapi(vardb.settings)
+			if preload_installed_pkgs:
+				for pkg in vardb:
+					self.spinner.update()
+					# This triggers metadata updates via FakeVartree.
+					vardb.aux_get(pkg.cpv, [])
+					fakedb.cpv_inject(pkg)
+
+			# Now that the vardb state is cached in our FakeVartree,
+			# we won't be needing the real vartree cache for awhile.
+			# To make some room on the heap, clear the vardbapi
+			# caches.
+			trees[myroot]["vartree"].dbapi._clear_cache()
+			gc.collect()
+
+			self.mydbapi[myroot] = fakedb
+			def graph_tree():
+				pass
+			graph_tree.dbapi = fakedb
+			self._graph_trees[myroot] = {}
+			self._filtered_trees[myroot] = {}
+			# Substitute the graph tree for the vartree in dep_check() since we
+			# want atom selections to be consistent with package selections
+			# have already been made.
+			self._graph_trees[myroot]["porttree"]   = graph_tree
+			self._graph_trees[myroot]["vartree"]    = graph_tree
+			def filtered_tree():
+				pass
+			filtered_tree.dbapi = self._dep_check_composite_db(self, myroot)
+			self._filtered_trees[myroot]["porttree"] = filtered_tree
+
+			# Passing in graph_tree as the vartree here could lead to better
+			# atom selections in some cases by causing atoms for packages that
+			# have been added to the graph to be preferred over other choices.
+			# However, it can trigger atom selections that result in
+			# unresolvable direct circular dependencies. For example, this
+			# happens with gwydion-dylan which depends on either itself or
+			# gwydion-dylan-bin. In case gwydion-dylan is not yet installed,
+			# gwydion-dylan-bin needs to be selected in order to avoid a
+			# an unresolvable direct circular dependency.
+			#
+			# To solve the problem described above, pass in "graph_db" so that
+			# packages that have been added to the graph are distinguishable
+			# from other available packages and installed packages. Also, pass
+			# the parent package into self._select_atoms() calls so that
+			# unresolvable direct circular dependencies can be detected and
+			# avoided when possible.
+			self._filtered_trees[myroot]["graph_db"] = graph_tree.dbapi
+			self._filtered_trees[myroot]["vartree"] = self.trees[myroot]["vartree"]
+
+			dbs = []
+			portdb = self.trees[myroot]["porttree"].dbapi
+			bindb  = self.trees[myroot]["bintree"].dbapi
+			vardb  = self.trees[myroot]["vartree"].dbapi
+			#               (db, pkg_type, built, installed, db_keys)
+			if "--usepkgonly" not in self.myopts:
+				db_keys = list(portdb._aux_cache_keys)
+				dbs.append((portdb, "ebuild", False, False, db_keys))
+			if "--usepkg" in self.myopts:
+				db_keys = list(bindb._aux_cache_keys)
+				dbs.append((bindb,  "binary", True, False, db_keys))
+			db_keys = list(trees[myroot]["vartree"].dbapi._aux_cache_keys)
+			dbs.append((vardb, "installed", True, True, db_keys))
+			self._filtered_trees[myroot]["dbs"] = dbs
+			if "--usepkg" in self.myopts:
+				self.trees[myroot]["bintree"].populate(
+					"--getbinpkg" in self.myopts,
+					"--getbinpkgonly" in self.myopts)
+		del trees
+
+		self.digraph=portage.digraph()
+		# contains all sets added to the graph
+		self._sets = {}
+		# contains atoms given as arguments
+		self._sets["args"] = InternalPackageSet()
+		# contains all atoms from all sets added to the graph, including
+		# atoms given as arguments
+		self._set_atoms = InternalPackageSet()
+		self._atom_arg_map = {}
+		# contains all nodes pulled in by self._set_atoms
+		self._set_nodes = set()
+		# Contains only Blocker -> Uninstall edges
+		self._blocker_uninstalls = digraph()
+		# Contains only Package -> Blocker edges
+		self._blocker_parents = digraph()
+		# Contains only irrelevant Package -> Blocker edges
+		self._irrelevant_blockers = digraph()
+		# Contains only unsolvable Package -> Blocker edges
+		self._unsolvable_blockers = digraph()
+		# Contains all Blocker -> Blocked Package edges
+		self._blocked_pkgs = digraph()
+		# Contains world packages that have been protected from
+		# uninstallation but may not have been added to the graph
+		# if the graph is not complete yet.
+		self._blocked_world_pkgs = {}
+		self._slot_collision_info = {}
+		# Slot collision nodes are not allowed to block other packages since
+		# blocker validation is only able to account for one package per slot.
+		self._slot_collision_nodes = set()
+		self._parent_atoms = {}
+		self._slot_conflict_parent_atoms = set()
+		self._serialized_tasks_cache = None
+		self._scheduler_graph = None
+		self._displayed_list = None
+		self._pprovided_args = []
+		self._missing_args = []
+		self._masked_installed = set()
+		self._unsatisfied_deps_for_display = []
+		self._unsatisfied_blockers_for_display = None
+		self._circular_deps_for_display = None
+		self._dep_stack = []
+		self._dep_disjunctive_stack = []
+		self._unsatisfied_deps = []
+		self._initially_unsatisfied_deps = []
+		self._ignored_deps = []
+		self._required_set_names = set(["system", "world"])
+		self._select_atoms = self._select_atoms_highest_available
+		self._select_package = self._select_pkg_highest_available
+		self._highest_pkg_cache = {}
+
+	def _show_slot_collision_notice(self):
+		"""Show an informational message advising the user to mask one of the
+		the packages. In some cases it may be possible to resolve this
+		automatically, but support for backtracking (removal nodes that have
+		already been selected) will be required in order to handle all possible
+		cases.
+		"""
+
+		if not self._slot_collision_info:
+			return
+
+		self._show_merge_list()
+
+		msg = []
+		msg.append("\n!!! Multiple package instances within a single " + \
+			"package slot have been pulled\n")
+		msg.append("!!! into the dependency graph, resulting" + \
+			" in a slot conflict:\n\n")
+		indent = "  "
+		# Max number of parents shown, to avoid flooding the display.
+		max_parents = 3
+		explanation_columns = 70
+		explanations = 0
+		for (slot_atom, root), slot_nodes \
+			in self._slot_collision_info.iteritems():
+			msg.append(str(slot_atom))
+			msg.append("\n\n")
+
+			for node in slot_nodes:
+				msg.append(indent)
+				msg.append(str(node))
+				parent_atoms = self._parent_atoms.get(node)
+				if parent_atoms:
+					pruned_list = set()
+					# Prefer conflict atoms over others.
+					for parent_atom in parent_atoms:
+						if len(pruned_list) >= max_parents:
+							break
+						if parent_atom in self._slot_conflict_parent_atoms:
+							pruned_list.add(parent_atom)
+
+					# If this package was pulled in by conflict atoms then
+					# show those alone since those are the most interesting.
+					if not pruned_list:
+						# When generating the pruned list, prefer instances
+						# of DependencyArg over instances of Package.
+						for parent_atom in parent_atoms:
+							if len(pruned_list) >= max_parents:
+								break
+							parent, atom = parent_atom
+							if isinstance(parent, DependencyArg):
+								pruned_list.add(parent_atom)
+						# Prefer Packages instances that themselves have been
+						# pulled into collision slots.
+						for parent_atom in parent_atoms:
+							if len(pruned_list) >= max_parents:
+								break
+							parent, atom = parent_atom
+							if isinstance(parent, Package) and \
+								(parent.slot_atom, parent.root) \
+								in self._slot_collision_info:
+								pruned_list.add(parent_atom)
+						for parent_atom in parent_atoms:
+							if len(pruned_list) >= max_parents:
+								break
+							pruned_list.add(parent_atom)
+					omitted_parents = len(parent_atoms) - len(pruned_list)
+					parent_atoms = pruned_list
+					msg.append(" pulled in by\n")
+					for parent_atom in parent_atoms:
+						parent, atom = parent_atom
+						msg.append(2*indent)
+						if isinstance(parent,
+							(PackageArg, AtomArg)):
+							# For PackageArg and AtomArg types, it's
+							# redundant to display the atom attribute.
+							msg.append(str(parent))
+						else:
+							# Display the specific atom from SetArg or
+							# Package types.
+							msg.append("%s required by %s" % (atom, parent))
+						msg.append("\n")
+					if omitted_parents:
+						msg.append(2*indent)
+						msg.append("(and %d more)\n" % omitted_parents)
+				else:
+					msg.append(" (no parents)\n")
+				msg.append("\n")
+			explanation = self._slot_conflict_explanation(slot_nodes)
+			if explanation:
+				explanations += 1
+				msg.append(indent + "Explanation:\n\n")
+				for line in textwrap.wrap(explanation, explanation_columns):
+					msg.append(2*indent + line + "\n")
+				msg.append("\n")
+		msg.append("\n")
+		sys.stderr.write("".join(msg))
+		sys.stderr.flush()
+
+		explanations_for_all = explanations == len(self._slot_collision_info)
+
+		if explanations_for_all or "--quiet" in self.myopts:
+			return
+
+		msg = []
+		msg.append("It may be possible to solve this problem ")
+		msg.append("by using package.mask to prevent one of ")
+		msg.append("those packages from being selected. ")
+		msg.append("However, it is also possible that conflicting ")
+		msg.append("dependencies exist such that they are impossible to ")
+		msg.append("satisfy simultaneously.  If such a conflict exists in ")
+		msg.append("the dependencies of two different packages, then those ")
+		msg.append("packages can not be installed simultaneously.")
+
+		from formatter import AbstractFormatter, DumbWriter
+		f = AbstractFormatter(DumbWriter(sys.stderr, maxcol=72))
+		for x in msg:
+			f.add_flowing_data(x)
+		f.end_paragraph(1)
+
+		msg = []
+		msg.append("For more information, see MASKED PACKAGES ")
+		msg.append("section in the emerge man page or refer ")
+		msg.append("to the Gentoo Handbook.")
+		for x in msg:
+			f.add_flowing_data(x)
+		f.end_paragraph(1)
+		f.writer.flush()
+
+	def _slot_conflict_explanation(self, slot_nodes):
+		"""
+		When a slot conflict occurs due to USE deps, there are a few
+		different cases to consider:
+
+		1) New USE are correctly set but --newuse wasn't requested so an
+		   installed package with incorrect USE happened to get pulled
+		   into graph before the new one.
+
+		2) New USE are incorrectly set but an installed package has correct
+		   USE so it got pulled into the graph, and a new instance also got
+		   pulled in due to --newuse or an upgrade.
+
+		3) Multiple USE deps exist that can't be satisfied simultaneously,
+		   and multiple package instances got pulled into the same slot to
+		   satisfy the conflicting deps.
+
+		Currently, explanations and suggested courses of action are generated
+		for cases 1 and 2. Case 3 is too complex to give a useful suggestion.
+		"""
+
+		if len(slot_nodes) != 2:
+			# Suggestions are only implemented for
+			# conflicts between two packages.
+			return None
+
+		all_conflict_atoms = self._slot_conflict_parent_atoms
+		matched_node = None
+		matched_atoms = None
+		unmatched_node = None
+		for node in slot_nodes:
+			parent_atoms = self._parent_atoms.get(node)
+			if not parent_atoms:
+				# Normally, there are always parent atoms. If there are
+				# none then something unexpected is happening and there's
+				# currently no suggestion for this case.
+				return None
+			conflict_atoms = all_conflict_atoms.intersection(parent_atoms)
+			for parent_atom in conflict_atoms:
+				parent, atom = parent_atom
+				if not atom.use:
+					# Suggestions are currently only implemented for cases
+					# in which all conflict atoms have USE deps.
+					return None
+			if conflict_atoms:
+				if matched_node is not None:
+					# If conflict atoms match multiple nodes
+					# then there's no suggestion.
+					return None
+				matched_node = node
+				matched_atoms = conflict_atoms
+			else:
+				if unmatched_node is not None:
+					# Neither node is matched by conflict atoms, and
+					# there is no suggestion for this case.
+					return None
+				unmatched_node = node
+
+		if matched_node is None or unmatched_node is None:
+			# This shouldn't happen.
+			return None
+
+		if unmatched_node.installed and not matched_node.installed and \
+			unmatched_node.cpv == matched_node.cpv:
+			# If the conflicting packages are the same version then
+			# --newuse should be all that's needed. If they are different
+			# versions then there's some other problem.
+			return "New USE are correctly set, but --newuse wasn't" + \
+				" requested, so an installed package with incorrect USE " + \
+				"happened to get pulled into the dependency graph. " + \
+				"In order to solve " + \
+				"this, either specify the --newuse option or explicitly " + \
+				" reinstall '%s'." % matched_node.slot_atom
+
+		if matched_node.installed and not unmatched_node.installed:
+			atoms = sorted(set(atom for parent, atom in matched_atoms))
+			explanation = ("New USE for '%s' are incorrectly set. " + \
+				"In order to solve this, adjust USE to satisfy '%s'") % \
+				(matched_node.slot_atom, atoms[0])
+			if len(atoms) > 1:
+				for atom in atoms[1:-1]:
+					explanation += ", '%s'" % (atom,)
+				if len(atoms) > 2:
+					explanation += ","
+				explanation += " and '%s'" % (atoms[-1],)
+			explanation += "."
+			return explanation
+
+		return None
+
+	def _process_slot_conflicts(self):
+		"""
+		Process slot conflict data to identify specific atoms which
+		lead to conflict. These atoms only match a subset of the
+		packages that have been pulled into a given slot.
+		"""
+		for (slot_atom, root), slot_nodes \
+			in self._slot_collision_info.iteritems():
+
+			all_parent_atoms = set()
+			for pkg in slot_nodes:
+				parent_atoms = self._parent_atoms.get(pkg)
+				if not parent_atoms:
+					continue
+				all_parent_atoms.update(parent_atoms)
+
+			for pkg in slot_nodes:
+				parent_atoms = self._parent_atoms.get(pkg)
+				if parent_atoms is None:
+					parent_atoms = set()
+					self._parent_atoms[pkg] = parent_atoms
+				for parent_atom in all_parent_atoms:
+					if parent_atom in parent_atoms:
+						continue
+					# Use package set for matching since it will match via
+					# PROVIDE when necessary, while match_from_list does not.
+					parent, atom = parent_atom
+					atom_set = InternalPackageSet(
+						initial_atoms=(atom,))
+					if atom_set.findAtomForPackage(pkg):
+						parent_atoms.add(parent_atom)
+					else:
+						self._slot_conflict_parent_atoms.add(parent_atom)
+
+	def _reinstall_for_flags(self, forced_flags,
+		orig_use, orig_iuse, cur_use, cur_iuse):
+		"""Return a set of flags that trigger reinstallation, or None if there
+		are no such flags."""
+		if "--newuse" in self.myopts:
+			flags = set(orig_iuse.symmetric_difference(
+				cur_iuse).difference(forced_flags))
+			flags.update(orig_iuse.intersection(orig_use).symmetric_difference(
+				cur_iuse.intersection(cur_use)))
+			if flags:
+				return flags
+		elif "changed-use" == self.myopts.get("--reinstall"):
+			flags = orig_iuse.intersection(orig_use).symmetric_difference(
+				cur_iuse.intersection(cur_use))
+			if flags:
+				return flags
+		return None
+
+	def _create_graph(self, allow_unsatisfied=False):
+		dep_stack = self._dep_stack
+		dep_disjunctive_stack = self._dep_disjunctive_stack
+		while dep_stack or dep_disjunctive_stack:
+			self.spinner.update()
+			while dep_stack:
+				dep = dep_stack.pop()
+				if isinstance(dep, Package):
+					if not self._add_pkg_deps(dep,
+						allow_unsatisfied=allow_unsatisfied):
+						return 0
+					continue
+				if not self._add_dep(dep, allow_unsatisfied=allow_unsatisfied):
+					return 0
+			if dep_disjunctive_stack:
+				if not self._pop_disjunction(allow_unsatisfied):
+					return 0
+		return 1
+
+	def _add_dep(self, dep, allow_unsatisfied=False):
+		debug = "--debug" in self.myopts
+		buildpkgonly = "--buildpkgonly" in self.myopts
+		nodeps = "--nodeps" in self.myopts
+		empty = "empty" in self.myparams
+		deep = "deep" in self.myparams
+		update = "--update" in self.myopts and dep.depth <= 1
+		if dep.blocker:
+			if not buildpkgonly and \
+				not nodeps and \
+				dep.parent not in self._slot_collision_nodes:
+				if dep.parent.onlydeps:
+					# It's safe to ignore blockers if the
+					# parent is an --onlydeps node.
+					return 1
+				# The blocker applies to the root where
+				# the parent is or will be installed.
+				blocker = Blocker(atom=dep.atom,
+					eapi=dep.parent.metadata["EAPI"],
+					root=dep.parent.root)
+				self._blocker_parents.add(blocker, dep.parent)
+			return 1
+		dep_pkg, existing_node = self._select_package(dep.root, dep.atom,
+			onlydeps=dep.onlydeps)
+		if not dep_pkg:
+			if dep.priority.optional:
+				# This could be an unecessary build-time dep
+				# pulled in by --with-bdeps=y.
+				return 1
+			if allow_unsatisfied:
+				self._unsatisfied_deps.append(dep)
+				return 1
+			self._unsatisfied_deps_for_display.append(
+				((dep.root, dep.atom), {"myparent":dep.parent}))
+			return 0
+		# In some cases, dep_check will return deps that shouldn't
+		# be proccessed any further, so they are identified and
+		# discarded here. Try to discard as few as possible since
+		# discarded dependencies reduce the amount of information
+		# available for optimization of merge order.
+		if dep.priority.satisfied and \
+			not dep_pkg.installed and \
+			not (existing_node or empty or deep or update):
+			myarg = None
+			if dep.root == self.target_root:
+				try:
+					myarg = self._iter_atoms_for_pkg(dep_pkg).next()
+				except StopIteration:
+					pass
+				except portage.exception.InvalidDependString:
+					if not dep_pkg.installed:
+						# This shouldn't happen since the package
+						# should have been masked.
+						raise
+			if not myarg:
+				self._ignored_deps.append(dep)
+				return 1
+
+		if not self._add_pkg(dep_pkg, dep):
+			return 0
+		return 1
+
+	def _add_pkg(self, pkg, dep):
+		myparent = None
+		priority = None
+		depth = 0
+		if dep is None:
+			dep = Dependency()
+		else:
+			myparent = dep.parent
+			priority = dep.priority
+			depth = dep.depth
+		if priority is None:
+			priority = DepPriority()
+		"""
+		Fills the digraph with nodes comprised of packages to merge.
+		mybigkey is the package spec of the package to merge.
+		myparent is the package depending on mybigkey ( or None )
+		addme = Should we add this package to the digraph or are we just looking at it's deps?
+			Think --onlydeps, we need to ignore packages in that case.
+		#stuff to add:
+		#SLOT-aware emerge
+		#IUSE-aware emerge -> USE DEP aware depgraph
+		#"no downgrade" emerge
+		"""
+		# Ensure that the dependencies of the same package
+		# are never processed more than once.
+		previously_added = pkg in self.digraph
+
+		# select the correct /var database that we'll be checking against
+		vardbapi = self.trees[pkg.root]["vartree"].dbapi
+		pkgsettings = self.pkgsettings[pkg.root]
+
+		arg_atoms = None
+		if True:
+			try:
+				arg_atoms = list(self._iter_atoms_for_pkg(pkg))
+			except portage.exception.InvalidDependString, e:
+				if not pkg.installed:
+					show_invalid_depstring_notice(
+						pkg, pkg.metadata["PROVIDE"], str(e))
+					return 0
+				del e
+
+		if not pkg.onlydeps:
+			if not pkg.installed and \
+				"empty" not in self.myparams and \
+				vardbapi.match(pkg.slot_atom):
+				# Increase the priority of dependencies on packages that
+				# are being rebuilt. This optimizes merge order so that
+				# dependencies are rebuilt/updated as soon as possible,
+				# which is needed especially when emerge is called by
+				# revdep-rebuild since dependencies may be affected by ABI
+				# breakage that has rendered them useless. Don't adjust
+				# priority here when in "empty" mode since all packages
+				# are being merged in that case.
+				priority.rebuild = True
+
+			existing_node = self._slot_pkg_map[pkg.root].get(pkg.slot_atom)
+			slot_collision = False
+			if existing_node:
+				existing_node_matches = pkg.cpv == existing_node.cpv
+				if existing_node_matches and \
+					pkg != existing_node and \
+					dep.atom is not None:
+					# Use package set for matching since it will match via
+					# PROVIDE when necessary, while match_from_list does not.
+					atom_set = InternalPackageSet(initial_atoms=[dep.atom])
+					if not atom_set.findAtomForPackage(existing_node):
+						existing_node_matches = False
+				if existing_node_matches:
+					# The existing node can be reused.
+					if arg_atoms:
+						for parent_atom in arg_atoms:
+							parent, atom = parent_atom
+							self.digraph.add(existing_node, parent,
+								priority=priority)
+							self._add_parent_atom(existing_node, parent_atom)
+					# If a direct circular dependency is not an unsatisfied
+					# buildtime dependency then drop it here since otherwise
+					# it can skew the merge order calculation in an unwanted
+					# way.
+					if existing_node != myparent or \
+						(priority.buildtime and not priority.satisfied):
+						self.digraph.addnode(existing_node, myparent,
+							priority=priority)
+						if dep.atom is not None and dep.parent is not None:
+							self._add_parent_atom(existing_node,
+								(dep.parent, dep.atom))
+					return 1
+				else:
+
+					# A slot collision has occurred.  Sometimes this coincides
+					# with unresolvable blockers, so the slot collision will be
+					# shown later if there are no unresolvable blockers.
+					self._add_slot_conflict(pkg)
+					slot_collision = True
+
+			if slot_collision:
+				# Now add this node to the graph so that self.display()
+				# can show use flags and --tree portage.output.  This node is
+				# only being partially added to the graph.  It must not be
+				# allowed to interfere with the other nodes that have been
+				# added.  Do not overwrite data for existing nodes in
+				# self.mydbapi since that data will be used for blocker
+				# validation.
+				# Even though the graph is now invalid, continue to process
+				# dependencies so that things like --fetchonly can still
+				# function despite collisions.
+				pass
+			elif not previously_added:
+				self._slot_pkg_map[pkg.root][pkg.slot_atom] = pkg
+				self.mydbapi[pkg.root].cpv_inject(pkg)
+				self._filtered_trees[pkg.root]["porttree"].dbapi._clear_cache()
+
+			if not pkg.installed:
+				# Allow this package to satisfy old-style virtuals in case it
+				# doesn't already. Any pre-existing providers will be preferred
+				# over this one.
+				try:
+					pkgsettings.setinst(pkg.cpv, pkg.metadata)
+					# For consistency, also update the global virtuals.
+					settings = self.roots[pkg.root].settings
+					settings.unlock()
+					settings.setinst(pkg.cpv, pkg.metadata)
+					settings.lock()
+				except portage.exception.InvalidDependString, e:
+					show_invalid_depstring_notice(
+						pkg, pkg.metadata["PROVIDE"], str(e))
+					del e
+					return 0
+
+		if arg_atoms:
+			self._set_nodes.add(pkg)
+
+		# Do this even when addme is False (--onlydeps) so that the
+		# parent/child relationship is always known in case
+		# self._show_slot_collision_notice() needs to be called later.
+		self.digraph.add(pkg, myparent, priority=priority)
+		if dep.atom is not None and dep.parent is not None:
+			self._add_parent_atom(pkg, (dep.parent, dep.atom))
+
+		if arg_atoms:
+			for parent_atom in arg_atoms:
+				parent, atom = parent_atom
+				self.digraph.add(pkg, parent, priority=priority)
+				self._add_parent_atom(pkg, parent_atom)
+
+		""" This section determines whether we go deeper into dependencies or not.
+		    We want to go deeper on a few occasions:
+		    Installing package A, we need to make sure package A's deps are met.
+		    emerge --deep <pkgspec>; we need to recursively check dependencies of pkgspec
+		    If we are in --nodeps (no recursion) mode, we obviously only check 1 level of dependencies.
+		"""
+		dep_stack = self._dep_stack
+		if "recurse" not in self.myparams:
+			return 1
+		elif pkg.installed and \
+			"deep" not in self.myparams:
+			dep_stack = self._ignored_deps
+
+		self.spinner.update()
+
+		if arg_atoms:
+			depth = 0
+		pkg.depth = depth
+		if not previously_added:
+			dep_stack.append(pkg)
+		return 1
+
+	def _add_parent_atom(self, pkg, parent_atom):
+		parent_atoms = self._parent_atoms.get(pkg)
+		if parent_atoms is None:
+			parent_atoms = set()
+			self._parent_atoms[pkg] = parent_atoms
+		parent_atoms.add(parent_atom)
+
+	def _add_slot_conflict(self, pkg):
+		self._slot_collision_nodes.add(pkg)
+		slot_key = (pkg.slot_atom, pkg.root)
+		slot_nodes = self._slot_collision_info.get(slot_key)
+		if slot_nodes is None:
+			slot_nodes = set()
+			slot_nodes.add(self._slot_pkg_map[pkg.root][pkg.slot_atom])
+			self._slot_collision_info[slot_key] = slot_nodes
+		slot_nodes.add(pkg)
+
+	def _add_pkg_deps(self, pkg, allow_unsatisfied=False):
+
+		mytype = pkg.type_name
+		myroot = pkg.root
+		mykey = pkg.cpv
+		metadata = pkg.metadata
+		myuse = pkg.use.enabled
+		jbigkey = pkg
+		depth = pkg.depth + 1
+		removal_action = "remove" in self.myparams
+
+		edepend={}
+		depkeys = ["DEPEND","RDEPEND","PDEPEND"]
+		for k in depkeys:
+			edepend[k] = metadata[k]
+
+		if not pkg.built and \
+			"--buildpkgonly" in self.myopts and \
+			"deep" not in self.myparams and \
+			"empty" not in self.myparams:
+			edepend["RDEPEND"] = ""
+			edepend["PDEPEND"] = ""
+		bdeps_optional = False
+
+		if pkg.built and not removal_action:
+			if self.myopts.get("--with-bdeps", "n") == "y":
+				# Pull in build time deps as requested, but marked them as
+				# "optional" since they are not strictly required. This allows
+				# more freedom in the merge order calculation for solving
+				# circular dependencies. Don't convert to PDEPEND since that
+				# could make --with-bdeps=y less effective if it is used to
+				# adjust merge order to prevent built_with_use() calls from
+				# failing.
+				bdeps_optional = True
+			else:
+				# built packages do not have build time dependencies.
+				edepend["DEPEND"] = ""
+
+		if removal_action and self.myopts.get("--with-bdeps", "y") == "n":
+			edepend["DEPEND"] = ""
+
+		bdeps_root = "/"
+		root_deps = self.myopts.get("--root-deps")
+		if root_deps is not None:
+			if root_deps is True:
+				bdeps_root = myroot
+			elif root_deps == "rdeps":
+				edepend["DEPEND"] = ""
+
+		deps = (
+			(bdeps_root, edepend["DEPEND"],
+				self._priority(buildtime=(not bdeps_optional),
+				optional=bdeps_optional)),
+			(myroot, edepend["RDEPEND"], self._priority(runtime=True)),
+			(myroot, edepend["PDEPEND"], self._priority(runtime_post=True))
+		)
+
+		debug = "--debug" in self.myopts
+		strict = mytype != "installed"
+		try:
+			if not strict:
+				portage.dep._dep_check_strict = False
+
+			for dep_root, dep_string, dep_priority in deps:
+				if not dep_string:
+					continue
+				if debug:
+					print
+					print "Parent:   ", jbigkey
+					print "Depstring:", dep_string
+					print "Priority:", dep_priority
+
+				try:
+
+					dep_string = portage.dep.paren_normalize(
+						portage.dep.use_reduce(
+						portage.dep.paren_reduce(dep_string),
+						uselist=pkg.use.enabled))
+
+					dep_string = list(self._queue_disjunctive_deps(
+						pkg, dep_root, dep_priority, dep_string))
+
+				except portage.exception.InvalidDependString, e:
+					if pkg.installed:
+						del e
+						continue
+					show_invalid_depstring_notice(pkg, dep_string, str(e))
+					return 0
+
+				if not dep_string:
+					continue
+
+				dep_string = portage.dep.paren_enclose(dep_string)
+
+				if not self._add_pkg_dep_string(
+					pkg, dep_root, dep_priority, dep_string,
+					allow_unsatisfied):
+					return 0
+
+		except portage.exception.AmbiguousPackageName, e:
+			pkgs = e.args[0]
+			portage.writemsg("\n\n!!! An atom in the dependencies " + \
+				"is not fully-qualified. Multiple matches:\n\n", noiselevel=-1)
+			for cpv in pkgs:
+				portage.writemsg("    %s\n" % cpv, noiselevel=-1)
+			portage.writemsg("\n", noiselevel=-1)
+			if mytype == "binary":
+				portage.writemsg(
+					"!!! This binary package cannot be installed: '%s'\n" % \
+					mykey, noiselevel=-1)
+			elif mytype == "ebuild":
+				portdb = self.roots[myroot].trees["porttree"].dbapi
+				myebuild, mylocation = portdb.findname2(mykey)
+				portage.writemsg("!!! This ebuild cannot be installed: " + \
+					"'%s'\n" % myebuild, noiselevel=-1)
+			portage.writemsg("!!! Please notify the package maintainer " + \
+				"that atoms must be fully-qualified.\n", noiselevel=-1)
+			return 0
+		finally:
+			portage.dep._dep_check_strict = True
+		return 1
+
+	def _add_pkg_dep_string(self, pkg, dep_root, dep_priority, dep_string,
+		allow_unsatisfied):
+		depth = pkg.depth + 1
+		debug = "--debug" in self.myopts
+		strict = pkg.type_name != "installed"
+
+		if debug:
+			print
+			print "Parent:   ", pkg
+			print "Depstring:", dep_string
+			print "Priority:", dep_priority
+
+		try:
+			selected_atoms = self._select_atoms(dep_root,
+				dep_string, myuse=pkg.use.enabled, parent=pkg,
+				strict=strict, priority=dep_priority)
+		except portage.exception.InvalidDependString, e:
+			show_invalid_depstring_notice(pkg, dep_string, str(e))
+			del e
+			if pkg.installed:
+				return 1
+			return 0
+
+		if debug:
+			print "Candidates:", selected_atoms
+
+		vardb = self.roots[dep_root].trees["vartree"].dbapi
+
+		for atom in selected_atoms:
+			try:
+
+				atom = portage.dep.Atom(atom)
+
+				mypriority = dep_priority.copy()
+				if not atom.blocker and vardb.match(atom):
+					mypriority.satisfied = True
+
+				if not self._add_dep(Dependency(atom=atom,
+					blocker=atom.blocker, depth=depth, parent=pkg,
+					priority=mypriority, root=dep_root),
+					allow_unsatisfied=allow_unsatisfied):
+					return 0
+
+			except portage.exception.InvalidAtom, e:
+				show_invalid_depstring_notice(
+					pkg, dep_string, str(e))
+				del e
+				if not pkg.installed:
+					return 0
+
+		if debug:
+			print "Exiting...", pkg
+
+		return 1
+
+	def _queue_disjunctive_deps(self, pkg, dep_root, dep_priority, dep_struct):
+		"""
+		Queue disjunctive (virtual and ||) deps in self._dep_disjunctive_stack.
+		Yields non-disjunctive deps. Raises InvalidDependString when 
+		necessary.
+		"""
+		i = 0
+		while i < len(dep_struct):
+			x = dep_struct[i]
+			if isinstance(x, list):
+				for y in self._queue_disjunctive_deps(
+					pkg, dep_root, dep_priority, x):
+					yield y
+			elif x == "||":
+				self._queue_disjunction(pkg, dep_root, dep_priority,
+					[ x, dep_struct[ i + 1 ] ] )
+				i += 1
+			else:
+				try:
+					x = portage.dep.Atom(x)
+				except portage.exception.InvalidAtom:
+					if not pkg.installed:
+						raise portage.exception.InvalidDependString(
+							"invalid atom: '%s'" % x)
+				else:
+					# Note: Eventually this will check for PROPERTIES=virtual
+					# or whatever other metadata gets implemented for this
+					# purpose.
+					if x.cp.startswith('virtual/'):
+						self._queue_disjunction( pkg, dep_root,
+							dep_priority, [ str(x) ] )
+					else:
+						yield str(x)
+			i += 1
+
+	def _queue_disjunction(self, pkg, dep_root, dep_priority, dep_struct):
+		self._dep_disjunctive_stack.append(
+			(pkg, dep_root, dep_priority, dep_struct))
+
+	def _pop_disjunction(self, allow_unsatisfied):
+		"""
+		Pop one disjunctive dep from self._dep_disjunctive_stack, and use it to
+		populate self._dep_stack.
+		"""
+		pkg, dep_root, dep_priority, dep_struct = \
+			self._dep_disjunctive_stack.pop()
+		dep_string = portage.dep.paren_enclose(dep_struct)
+		if not self._add_pkg_dep_string(
+			pkg, dep_root, dep_priority, dep_string, allow_unsatisfied):
+			return 0
+		return 1
+
+	def _priority(self, **kwargs):
+		if "remove" in self.myparams:
+			priority_constructor = UnmergeDepPriority
+		else:
+			priority_constructor = DepPriority
+		return priority_constructor(**kwargs)
+
+	def _dep_expand(self, root_config, atom_without_category):
+		"""
+		@param root_config: a root config instance
+		@type root_config: RootConfig
+		@param atom_without_category: an atom without a category component
+		@type atom_without_category: String
+		@rtype: list
+		@returns: a list of atoms containing categories (possibly empty)
+		"""
+		null_cp = portage.dep_getkey(insert_category_into_atom(
+			atom_without_category, "null"))
+		cat, atom_pn = portage.catsplit(null_cp)
+
+		dbs = self._filtered_trees[root_config.root]["dbs"]
+		categories = set()
+		for db, pkg_type, built, installed, db_keys in dbs:
+			for cat in db.categories:
+				if db.cp_list("%s/%s" % (cat, atom_pn)):
+					categories.add(cat)
+
+		deps = []
+		for cat in categories:
+			deps.append(insert_category_into_atom(
+				atom_without_category, cat))
+		return deps
+
+	def _have_new_virt(self, root, atom_cp):
+		ret = False
+		for db, pkg_type, built, installed, db_keys in \
+			self._filtered_trees[root]["dbs"]:
+			if db.cp_list(atom_cp):
+				ret = True
+				break
+		return ret
+
+	def _iter_atoms_for_pkg(self, pkg):
+		# TODO: add multiple $ROOT support
+		if pkg.root != self.target_root:
+			return
+		atom_arg_map = self._atom_arg_map
+		root_config = self.roots[pkg.root]
+		for atom in self._set_atoms.iterAtomsForPackage(pkg):
+			atom_cp = portage.dep_getkey(atom)
+			if atom_cp != pkg.cp and \
+				self._have_new_virt(pkg.root, atom_cp):
+				continue
+			visible_pkgs = root_config.visible_pkgs.match_pkgs(atom)
+			visible_pkgs.reverse() # descending order
+			higher_slot = None
+			for visible_pkg in visible_pkgs:
+				if visible_pkg.cp != atom_cp:
+					continue
+				if pkg >= visible_pkg:
+					# This is descending order, and we're not
+					# interested in any versions <= pkg given.
+					break
+				if pkg.slot_atom != visible_pkg.slot_atom:
+					higher_slot = visible_pkg
+					break
+			if higher_slot is not None:
+				continue
+			for arg in atom_arg_map[(atom, pkg.root)]:
+				if isinstance(arg, PackageArg) and \
+					arg.package != pkg:
+					continue
+				yield arg, atom
+
+	def select_files(self, myfiles):
+		"""Given a list of .tbz2s, .ebuilds sets, and deps, create the
+		appropriate depgraph and return a favorite list."""
+		debug = "--debug" in self.myopts
+		root_config = self.roots[self.target_root]
+		sets = root_config.sets
+		getSetAtoms = root_config.setconfig.getSetAtoms
+		myfavorites=[]
+		myroot = self.target_root
+		dbs = self._filtered_trees[myroot]["dbs"]
+		vardb = self.trees[myroot]["vartree"].dbapi
+		real_vardb = self._trees_orig[myroot]["vartree"].dbapi
+		portdb = self.trees[myroot]["porttree"].dbapi
+		bindb = self.trees[myroot]["bintree"].dbapi
+		pkgsettings = self.pkgsettings[myroot]
+		args = []
+		onlydeps = "--onlydeps" in self.myopts
+		lookup_owners = []
+		for x in myfiles:
+			ext = os.path.splitext(x)[1]
+			if ext==".tbz2":
+				if not os.path.exists(x):
+					if os.path.exists(
+						os.path.join(pkgsettings["PKGDIR"], "All", x)):
+						x = os.path.join(pkgsettings["PKGDIR"], "All", x)
+					elif os.path.exists(
+						os.path.join(pkgsettings["PKGDIR"], x)):
+						x = os.path.join(pkgsettings["PKGDIR"], x)
+					else:
+						print "\n\n!!! Binary package '"+str(x)+"' does not exist."
+						print "!!! Please ensure the tbz2 exists as specified.\n"
+						return 0, myfavorites
+				mytbz2=portage.xpak.tbz2(x)
+				mykey=mytbz2.getelements("CATEGORY")[0]+"/"+os.path.splitext(os.path.basename(x))[0]
+				if os.path.realpath(x) != \
+					os.path.realpath(self.trees[myroot]["bintree"].getname(mykey)):
+					print colorize("BAD", "\n*** You need to adjust PKGDIR to emerge this package.\n")
+					return 0, myfavorites
+				db_keys = list(bindb._aux_cache_keys)
+				metadata = izip(db_keys, bindb.aux_get(mykey, db_keys))
+				pkg = Package(type_name="binary", root_config=root_config,
+					cpv=mykey, built=True, metadata=metadata,
+					onlydeps=onlydeps)
+				self._pkg_cache[pkg] = pkg
+				args.append(PackageArg(arg=x, package=pkg,
+					root_config=root_config))
+			elif ext==".ebuild":
+				ebuild_path = portage.util.normalize_path(os.path.abspath(x))
+				pkgdir = os.path.dirname(ebuild_path)
+				tree_root = os.path.dirname(os.path.dirname(pkgdir))
+				cp = pkgdir[len(tree_root)+1:]
+				e = portage.exception.PackageNotFound(
+					("%s is not in a valid portage tree " + \
+					"hierarchy or does not exist") % x)
+				if not portage.isvalidatom(cp):
+					raise e
+				cat = portage.catsplit(cp)[0]
+				mykey = cat + "/" + os.path.basename(ebuild_path[:-7])
+				if not portage.isvalidatom("="+mykey):
+					raise e
+				ebuild_path = portdb.findname(mykey)
+				if ebuild_path:
+					if ebuild_path != os.path.join(os.path.realpath(tree_root),
+						cp, os.path.basename(ebuild_path)):
+						print colorize("BAD", "\n*** You need to adjust PORTDIR or PORTDIR_OVERLAY to emerge this package.\n")
+						return 0, myfavorites
+					if mykey not in portdb.xmatch(
+						"match-visible", portage.dep_getkey(mykey)):
+						print colorize("BAD", "\n*** You are emerging a masked package. It is MUCH better to use")
+						print colorize("BAD", "*** /etc/portage/package.* to accomplish this. See portage(5) man")
+						print colorize("BAD", "*** page for details.")
+						countdown(int(self.settings["EMERGE_WARNING_DELAY"]),
+							"Continuing...")
+				else:
+					raise portage.exception.PackageNotFound(
+						"%s is not in a valid portage tree hierarchy or does not exist" % x)
+				db_keys = list(portdb._aux_cache_keys)
+				metadata = izip(db_keys, portdb.aux_get(mykey, db_keys))
+				pkg = Package(type_name="ebuild", root_config=root_config,
+					cpv=mykey, metadata=metadata, onlydeps=onlydeps)
+				pkgsettings.setcpv(pkg)
+				pkg.metadata["USE"] = pkgsettings["PORTAGE_USE"]
+				pkg.metadata['CHOST'] = pkgsettings.get('CHOST', '')
+				self._pkg_cache[pkg] = pkg
+				args.append(PackageArg(arg=x, package=pkg,
+					root_config=root_config))
+			elif x.startswith(os.path.sep):
+				if not x.startswith(myroot):
+					portage.writemsg(("\n\n!!! '%s' does not start with" + \
+						" $ROOT.\n") % x, noiselevel=-1)
+					return 0, []
+				# Queue these up since it's most efficient to handle
+				# multiple files in a single iter_owners() call.
+				lookup_owners.append(x)
+			else:
+				if x in ("system", "world"):
+					x = SETPREFIX + x
+				if x.startswith(SETPREFIX):
+					s = x[len(SETPREFIX):]
+					if s not in sets:
+						raise portage.exception.PackageSetNotFound(s)
+					if s in self._sets:
+						continue
+					# Recursively expand sets so that containment tests in
+					# self._get_parent_sets() properly match atoms in nested
+					# sets (like if world contains system).
+					expanded_set = InternalPackageSet(
+						initial_atoms=getSetAtoms(s))
+					self._sets[s] = expanded_set
+					args.append(SetArg(arg=x, set=expanded_set,
+						root_config=root_config))
+					continue
+				if not is_valid_package_atom(x):
+					portage.writemsg("\n\n!!! '%s' is not a valid package atom.\n" % x,
+						noiselevel=-1)
+					portage.writemsg("!!! Please check ebuild(5) for full details.\n")
+					portage.writemsg("!!! (Did you specify a version but forget to prefix with '='?)\n")
+					return (0,[])
+				# Don't expand categories or old-style virtuals here unless
+				# necessary. Expansion of old-style virtuals here causes at
+				# least the following problems:
+				#   1) It's more difficult to determine which set(s) an atom
+				#      came from, if any.
+				#   2) It takes away freedom from the resolver to choose other
+				#      possible expansions when necessary.
+				if "/" in x:
+					args.append(AtomArg(arg=x, atom=x,
+						root_config=root_config))
+					continue
+				expanded_atoms = self._dep_expand(root_config, x)
+				installed_cp_set = set()
+				for atom in expanded_atoms:
+					atom_cp = portage.dep_getkey(atom)
+					if vardb.cp_list(atom_cp):
+						installed_cp_set.add(atom_cp)
+
+				if len(installed_cp_set) > 1:
+					non_virtual_cps = set()
+					for atom_cp in installed_cp_set:
+						if not atom_cp.startswith("virtual/"):
+							non_virtual_cps.add(atom_cp)
+					if len(non_virtual_cps) == 1:
+						installed_cp_set = non_virtual_cps
+
+				if len(expanded_atoms) > 1 and len(installed_cp_set) == 1:
+					installed_cp = iter(installed_cp_set).next()
+					expanded_atoms = [atom for atom in expanded_atoms \
+						if portage.dep_getkey(atom) == installed_cp]
+
+				if len(expanded_atoms) > 1:
+					print
+					print
+					ambiguous_package_name(x, expanded_atoms, root_config,
+						self.spinner, self.myopts)
+					return False, myfavorites
+				if expanded_atoms:
+					atom = expanded_atoms[0]
+				else:
+					null_atom = insert_category_into_atom(x, "null")
+					null_cp = portage.dep_getkey(null_atom)
+					cat, atom_pn = portage.catsplit(null_cp)
+					virts_p = root_config.settings.get_virts_p().get(atom_pn)
+					if virts_p:
+						# Allow the depgraph to choose which virtual.
+						atom = insert_category_into_atom(x, "virtual")
+					else:
+						atom = insert_category_into_atom(x, "null")
+
+				args.append(AtomArg(arg=x, atom=atom,
+					root_config=root_config))
+
+		if lookup_owners:
+			relative_paths = []
+			search_for_multiple = False
+			if len(lookup_owners) > 1:
+				search_for_multiple = True
+
+			for x in lookup_owners:
+				if not search_for_multiple and os.path.isdir(x):
+					search_for_multiple = True
+				relative_paths.append(x[len(myroot):])
+
+			owners = set()
+			for pkg, relative_path in \
+				real_vardb._owners.iter_owners(relative_paths):
+				owners.add(pkg.mycpv)
+				if not search_for_multiple:
+					break
+
+			if not owners:
+				portage.writemsg(("\n\n!!! '%s' is not claimed " + \
+					"by any package.\n") % lookup_owners[0], noiselevel=-1)
+				return 0, []
+
+			for cpv in owners:
+				slot = vardb.aux_get(cpv, ["SLOT"])[0]
+				if not slot:
+					# portage now masks packages with missing slot, but it's
+					# possible that one was installed by an older version
+					atom = portage.cpv_getkey(cpv)
+				else:
+					atom = "%s:%s" % (portage.cpv_getkey(cpv), slot)
+				args.append(AtomArg(arg=atom, atom=atom,
+					root_config=root_config))
+
+		if "--update" in self.myopts:
+			# In some cases, the greedy slots behavior can pull in a slot that
+			# the user would want to uninstall due to it being blocked by a
+			# newer version in a different slot. Therefore, it's necessary to
+			# detect and discard any that should be uninstalled. Each time
+			# that arguments are updated, package selections are repeated in
+			# order to ensure consistency with the current arguments:
+			#
+			#  1) Initialize args
+			#  2) Select packages and generate initial greedy atoms
+			#  3) Update args with greedy atoms
+			#  4) Select packages and generate greedy atoms again, while
+			#     accounting for any blockers between selected packages
+			#  5) Update args with revised greedy atoms
+
+			self._set_args(args)
+			greedy_args = []
+			for arg in args:
+				greedy_args.append(arg)
+				if not isinstance(arg, AtomArg):
+					continue
+				for atom in self._greedy_slots(arg.root_config, arg.atom):
+					greedy_args.append(
+						AtomArg(arg=arg.arg, atom=atom,
+							root_config=arg.root_config))
+
+			self._set_args(greedy_args)
+			del greedy_args
+
+			# Revise greedy atoms, accounting for any blockers
+			# between selected packages.
+			revised_greedy_args = []
+			for arg in args:
+				revised_greedy_args.append(arg)
+				if not isinstance(arg, AtomArg):
+					continue
+				for atom in self._greedy_slots(arg.root_config, arg.atom,
+					blocker_lookahead=True):
+					revised_greedy_args.append(
+						AtomArg(arg=arg.arg, atom=atom,
+							root_config=arg.root_config))
+			args = revised_greedy_args
+			del revised_greedy_args
+
+		self._set_args(args)
+
+		myfavorites = set(myfavorites)
+		for arg in args:
+			if isinstance(arg, (AtomArg, PackageArg)):
+				myfavorites.add(arg.atom)
+			elif isinstance(arg, SetArg):
+				myfavorites.add(arg.arg)
+		myfavorites = list(myfavorites)
+
+		pprovideddict = pkgsettings.pprovideddict
+		if debug:
+			portage.writemsg("\n", noiselevel=-1)
+		# Order needs to be preserved since a feature of --nodeps
+		# is to allow the user to force a specific merge order.
+		args.reverse()
+		while args:
+			arg = args.pop()
+			for atom in arg.set:
+				self.spinner.update()
+				dep = Dependency(atom=atom, onlydeps=onlydeps,
+					root=myroot, parent=arg)
+				atom_cp = portage.dep_getkey(atom)
+				try:
+					pprovided = pprovideddict.get(portage.dep_getkey(atom))
+					if pprovided and portage.match_from_list(atom, pprovided):
+						# A provided package has been specified on the command line.
+						self._pprovided_args.append((arg, atom))
+						continue
+					if isinstance(arg, PackageArg):
+						if not self._add_pkg(arg.package, dep) or \
+							not self._create_graph():
+							sys.stderr.write(("\n\n!!! Problem resolving " + \
+								"dependencies for %s\n") % arg.arg)
+							return 0, myfavorites
+						continue
+					if debug:
+						portage.writemsg("      Arg: %s\n     Atom: %s\n" % \
+							(arg, atom), noiselevel=-1)
+					pkg, existing_node = self._select_package(
+						myroot, atom, onlydeps=onlydeps)
+					if not pkg:
+						if not (isinstance(arg, SetArg) and \
+							arg.name in ("system", "world")):
+							self._unsatisfied_deps_for_display.append(
+								((myroot, atom), {}))
+							return 0, myfavorites
+						self._missing_args.append((arg, atom))
+						continue
+					if atom_cp != pkg.cp:
+						# For old-style virtuals, we need to repeat the
+						# package.provided check against the selected package.
+						expanded_atom = atom.replace(atom_cp, pkg.cp)
+						pprovided = pprovideddict.get(pkg.cp)
+						if pprovided and \
+							portage.match_from_list(expanded_atom, pprovided):
+							# A provided package has been
+							# specified on the command line.
+							self._pprovided_args.append((arg, atom))
+							continue
+					if pkg.installed and "selective" not in self.myparams:
+						self._unsatisfied_deps_for_display.append(
+							((myroot, atom), {}))
+						# Previous behavior was to bail out in this case, but
+						# since the dep is satisfied by the installed package,
+						# it's more friendly to continue building the graph
+						# and just show a warning message. Therefore, only bail
+						# out here if the atom is not from either the system or
+						# world set.
+						if not (isinstance(arg, SetArg) and \
+							arg.name in ("system", "world")):
+							return 0, myfavorites
+
+					# Add the selected package to the graph as soon as possible
+					# so that later dep_check() calls can use it as feedback
+					# for making more consistent atom selections.
+					if not self._add_pkg(pkg, dep):
+						if isinstance(arg, SetArg):
+							sys.stderr.write(("\n\n!!! Problem resolving " + \
+								"dependencies for %s from %s\n") % \
+								(atom, arg.arg))
+						else:
+							sys.stderr.write(("\n\n!!! Problem resolving " + \
+								"dependencies for %s\n") % atom)
+						return 0, myfavorites
+
+				except portage.exception.MissingSignature, e:
+					portage.writemsg("\n\n!!! A missing gpg signature is preventing portage from calculating the\n")
+					portage.writemsg("!!! required dependencies. This is a security feature enabled by the admin\n")
+					portage.writemsg("!!! to aid in the detection of malicious intent.\n\n")
+					portage.writemsg("!!! THIS IS A POSSIBLE INDICATION OF TAMPERED FILES -- CHECK CAREFULLY.\n")
+					portage.writemsg("!!! Affected file: %s\n" % (e), noiselevel=-1)
+					return 0, myfavorites
+				except portage.exception.InvalidSignature, e:
+					portage.writemsg("\n\n!!! An invalid gpg signature is preventing portage from calculating the\n")
+					portage.writemsg("!!! required dependencies. This is a security feature enabled by the admin\n")
+					portage.writemsg("!!! to aid in the detection of malicious intent.\n\n")
+					portage.writemsg("!!! THIS IS A POSSIBLE INDICATION OF TAMPERED FILES -- CHECK CAREFULLY.\n")
+					portage.writemsg("!!! Affected file: %s\n" % (e), noiselevel=-1)
+					return 0, myfavorites
+				except SystemExit, e:
+					raise # Needed else can't exit
+				except Exception, e:
+					print >> sys.stderr, "\n\n!!! Problem in '%s' dependencies." % atom
+					print >> sys.stderr, "!!!", str(e), getattr(e, "__module__", None)
+					raise
+
+		# Now that the root packages have been added to the graph,
+		# process the dependencies.
+		if not self._create_graph():
+			return 0, myfavorites
+
+		missing=0
+		if "--usepkgonly" in self.myopts:
+			for xs in self.digraph.all_nodes():
+				if not isinstance(xs, Package):
+					continue
+				if len(xs) >= 4 and xs[0] != "binary" and xs[3] == "merge":
+					if missing == 0:
+						print
+					missing += 1
+					print "Missing binary for:",xs[2]
+
+		try:
+			self.altlist()
+		except self._unknown_internal_error:
+			return False, myfavorites
+
+		# We're true here unless we are missing binaries.
+		return (not missing,myfavorites)
+
+	def _set_args(self, args):
+		"""
+		Create the "args" package set from atoms and packages given as
+		arguments. This method can be called multiple times if necessary.
+		The package selection cache is automatically invalidated, since
+		arguments influence package selections.
+		"""
+		args_set = self._sets["args"]
+		args_set.clear()
+		for arg in args:
+			if not isinstance(arg, (AtomArg, PackageArg)):
+				continue
+			atom = arg.atom
+			if atom in args_set:
+				continue
+			args_set.add(atom)
+
+		self._set_atoms.clear()
+		self._set_atoms.update(chain(*self._sets.itervalues()))
+		atom_arg_map = self._atom_arg_map
+		atom_arg_map.clear()
+		for arg in args:
+			for atom in arg.set:
+				atom_key = (atom, arg.root_config.root)
+				refs = atom_arg_map.get(atom_key)
+				if refs is None:
+					refs = []
+					atom_arg_map[atom_key] = refs
+					if arg not in refs:
+						refs.append(arg)
+
+		# Invalidate the package selection cache, since
+		# arguments influence package selections.
+		self._highest_pkg_cache.clear()
+		for trees in self._filtered_trees.itervalues():
+			trees["porttree"].dbapi._clear_cache()
+
+	def _greedy_slots(self, root_config, atom, blocker_lookahead=False):
+		"""
+		Return a list of slot atoms corresponding to installed slots that
+		differ from the slot of the highest visible match. When
+		blocker_lookahead is True, slot atoms that would trigger a blocker
+		conflict are automatically discarded, potentially allowing automatic
+		uninstallation of older slots when appropriate.
+		"""
+		highest_pkg, in_graph = self._select_package(root_config.root, atom)
+		if highest_pkg is None:
+			return []
+		vardb = root_config.trees["vartree"].dbapi
+		slots = set()
+		for cpv in vardb.match(atom):
+			# don't mix new virtuals with old virtuals
+			if portage.cpv_getkey(cpv) == highest_pkg.cp:
+				slots.add(vardb.aux_get(cpv, ["SLOT"])[0])
+
+		slots.add(highest_pkg.metadata["SLOT"])
+		if len(slots) == 1:
+			return []
+		greedy_pkgs = []
+		slots.remove(highest_pkg.metadata["SLOT"])
+		while slots:
+			slot = slots.pop()
+			slot_atom = portage.dep.Atom("%s:%s" % (highest_pkg.cp, slot))
+			pkg, in_graph = self._select_package(root_config.root, slot_atom)
+			if pkg is not None and \
+				pkg.cp == highest_pkg.cp and pkg < highest_pkg:
+				greedy_pkgs.append(pkg)
+		if not greedy_pkgs:
+			return []
+		if not blocker_lookahead:
+			return [pkg.slot_atom for pkg in greedy_pkgs]
+
+		blockers = {}
+		blocker_dep_keys = ["DEPEND", "PDEPEND", "RDEPEND"]
+		for pkg in greedy_pkgs + [highest_pkg]:
+			dep_str = " ".join(pkg.metadata[k] for k in blocker_dep_keys)
+			try:
+				atoms = self._select_atoms(
+					pkg.root, dep_str, pkg.use.enabled,
+					parent=pkg, strict=True)
+			except portage.exception.InvalidDependString:
+				continue
+			blocker_atoms = (x for x in atoms if x.blocker)
+			blockers[pkg] = InternalPackageSet(initial_atoms=blocker_atoms)
+
+		if highest_pkg not in blockers:
+			return []
+
+		# filter packages with invalid deps
+		greedy_pkgs = [pkg for pkg in greedy_pkgs if pkg in blockers]
+
+		# filter packages that conflict with highest_pkg
+		greedy_pkgs = [pkg for pkg in greedy_pkgs if not \
+			(blockers[highest_pkg].findAtomForPackage(pkg) or \
+			blockers[pkg].findAtomForPackage(highest_pkg))]
+
+		if not greedy_pkgs:
+			return []
+
+		# If two packages conflict, discard the lower version.
+		discard_pkgs = set()
+		greedy_pkgs.sort(reverse=True)
+		for i in xrange(len(greedy_pkgs) - 1):
+			pkg1 = greedy_pkgs[i]
+			if pkg1 in discard_pkgs:
+				continue
+			for j in xrange(i + 1, len(greedy_pkgs)):
+				pkg2 = greedy_pkgs[j]
+				if pkg2 in discard_pkgs:
+					continue
+				if blockers[pkg1].findAtomForPackage(pkg2) or \
+					blockers[pkg2].findAtomForPackage(pkg1):
+					# pkg1 > pkg2
+					discard_pkgs.add(pkg2)
+
+		return [pkg.slot_atom for pkg in greedy_pkgs \
+			if pkg not in discard_pkgs]
+
+	def _select_atoms_from_graph(self, *pargs, **kwargs):
+		"""
+		Prefer atoms matching packages that have already been
+		added to the graph or those that are installed and have
+		not been scheduled for replacement.
+		"""
+		kwargs["trees"] = self._graph_trees
+		return self._select_atoms_highest_available(*pargs, **kwargs)
+
+	def _select_atoms_highest_available(self, root, depstring,
+		myuse=None, parent=None, strict=True, trees=None, priority=None):
+		"""This will raise InvalidDependString if necessary. If trees is
+		None then self._filtered_trees is used."""
+		pkgsettings = self.pkgsettings[root]
+		if trees is None:
+			trees = self._filtered_trees
+		if not getattr(priority, "buildtime", False):
+			# The parent should only be passed to dep_check() for buildtime
+			# dependencies since that's the only case when it's appropriate
+			# to trigger the circular dependency avoidance code which uses it.
+			# It's important not to trigger the same circular dependency
+			# avoidance code for runtime dependencies since it's not needed
+			# and it can promote an incorrect package choice.
+			parent = None
+		if True:
+			try:
+				if parent is not None:
+					trees[root]["parent"] = parent
+				if not strict:
+					portage.dep._dep_check_strict = False
+				mycheck = portage.dep_check(depstring, None,
+					pkgsettings, myuse=myuse,
+					myroot=root, trees=trees)
+			finally:
+				if parent is not None:
+					trees[root].pop("parent")
+				portage.dep._dep_check_strict = True
+			if not mycheck[0]:
+				raise portage.exception.InvalidDependString(mycheck[1])
+			selected_atoms = mycheck[1]
+		return selected_atoms
+
+	def _show_unsatisfied_dep(self, root, atom, myparent=None, arg=None):
+		atom = portage.dep.Atom(atom)
+		atom_set = InternalPackageSet(initial_atoms=(atom,))
+		atom_without_use = atom
+		if atom.use:
+			atom_without_use = portage.dep.remove_slot(atom)
+			if atom.slot:
+				atom_without_use += ":" + atom.slot
+			atom_without_use = portage.dep.Atom(atom_without_use)
+		xinfo = '"%s"' % atom
+		if arg:
+			xinfo='"%s"' % arg
+		# Discard null/ from failed cpv_expand category expansion.
+		xinfo = xinfo.replace("null/", "")
+		masked_packages = []
+		missing_use = []
+		masked_pkg_instances = set()
+		missing_licenses = []
+		have_eapi_mask = False
+		pkgsettings = self.pkgsettings[root]
+		implicit_iuse = pkgsettings._get_implicit_iuse()
+		root_config = self.roots[root]
+		portdb = self.roots[root].trees["porttree"].dbapi
+		dbs = self._filtered_trees[root]["dbs"]
+		for db, pkg_type, built, installed, db_keys in dbs:
+			if installed:
+				continue
+			match = db.match
+			if hasattr(db, "xmatch"):
+				cpv_list = db.xmatch("match-all", atom_without_use)
+			else:
+				cpv_list = db.match(atom_without_use)
+			# descending order
+			cpv_list.reverse()
+			for cpv in cpv_list:
+				metadata, mreasons  = get_mask_info(root_config, cpv,
+					pkgsettings, db, pkg_type, built, installed, db_keys)
+				if metadata is not None:
+					pkg = Package(built=built, cpv=cpv,
+						installed=installed, metadata=metadata,
+						root_config=root_config)
+					if pkg.cp != atom.cp:
+						# A cpv can be returned from dbapi.match() as an
+						# old-style virtual match even in cases when the
+						# package does not actually PROVIDE the virtual.
+						# Filter out any such false matches here.
+						if not atom_set.findAtomForPackage(pkg):
+							continue
+					if mreasons:
+						masked_pkg_instances.add(pkg)
+					if atom.use:
+						missing_use.append(pkg)
+						if not mreasons:
+							continue
+				masked_packages.append(
+					(root_config, pkgsettings, cpv, metadata, mreasons))
+
+		missing_use_reasons = []
+		missing_iuse_reasons = []
+		for pkg in missing_use:
+			use = pkg.use.enabled
+			iuse = implicit_iuse.union(re.escape(x) for x in pkg.iuse.all)
+			iuse_re = re.compile("^(%s)$" % "|".join(iuse))
+			missing_iuse = []
+			for x in atom.use.required:
+				if iuse_re.match(x) is None:
+					missing_iuse.append(x)
+			mreasons = []
+			if missing_iuse:
+				mreasons.append("Missing IUSE: %s" % " ".join(missing_iuse))
+				missing_iuse_reasons.append((pkg, mreasons))
+			else:
+				need_enable = sorted(atom.use.enabled.difference(use))
+				need_disable = sorted(atom.use.disabled.intersection(use))
+				if need_enable or need_disable:
+					changes = []
+					changes.extend(colorize("red", "+" + x) \
+						for x in need_enable)
+					changes.extend(colorize("blue", "-" + x) \
+						for x in need_disable)
+					mreasons.append("Change USE: %s" % " ".join(changes))
+					missing_use_reasons.append((pkg, mreasons))
+
+		unmasked_use_reasons = [(pkg, mreasons) for (pkg, mreasons) \
+			in missing_use_reasons if pkg not in masked_pkg_instances]
+
+		unmasked_iuse_reasons = [(pkg, mreasons) for (pkg, mreasons) \
+			in missing_iuse_reasons if pkg not in masked_pkg_instances]
+
+		show_missing_use = False
+		if unmasked_use_reasons:
+			# Only show the latest version.
+			show_missing_use = unmasked_use_reasons[:1]
+		elif unmasked_iuse_reasons:
+			if missing_use_reasons:
+				# All packages with required IUSE are masked,
+				# so display a normal masking message.
+				pass
+			else:
+				show_missing_use = unmasked_iuse_reasons
+
+		if show_missing_use:
+			print "\nemerge: there are no ebuilds built with USE flags to satisfy "+green(xinfo)+"."
+			print "!!! One of the following packages is required to complete your request:"
+			for pkg, mreasons in show_missing_use:
+				print "- "+pkg.cpv+" ("+", ".join(mreasons)+")"
+
+		elif masked_packages:
+			print "\n!!! " + \
+				colorize("BAD", "All ebuilds that could satisfy ") + \
+				colorize("INFORM", xinfo) + \
+				colorize("BAD", " have been masked.")
+			print "!!! One of the following masked packages is required to complete your request:"
+			have_eapi_mask = show_masked_packages(masked_packages)
+			if have_eapi_mask:
+				print
+				msg = ("The current version of portage supports " + \
+					"EAPI '%s'. You must upgrade to a newer version" + \
+					" of portage before EAPI masked packages can" + \
+					" be installed.") % portage.const.EAPI
+				from textwrap import wrap
+				for line in wrap(msg, 75):
+					print line
+			print
+			show_mask_docs()
+		else:
+			print "\nemerge: there are no ebuilds to satisfy "+green(xinfo)+"."
+
+		# Show parent nodes and the argument that pulled them in.
+		traversed_nodes = set()
+		node = myparent
+		msg = []
+		while node is not None:
+			traversed_nodes.add(node)
+			msg.append('(dependency required by "%s" [%s])' % \
+				(colorize('INFORM', str(node.cpv)), node.type_name))
+			# When traversing to parents, prefer arguments over packages
+			# since arguments are root nodes. Never traverse the same
+			# package twice, in order to prevent an infinite loop.
+			selected_parent = None
+			for parent in self.digraph.parent_nodes(node):
+				if isinstance(parent, DependencyArg):
+					msg.append('(dependency required by "%s" [argument])' % \
+						(colorize('INFORM', str(parent))))
+					selected_parent = None
+					break
+				if parent not in traversed_nodes:
+					selected_parent = parent
+			node = selected_parent
+		for line in msg:
+			print line
+
+		print
+
+	def _select_pkg_highest_available(self, root, atom, onlydeps=False):
+		cache_key = (root, atom, onlydeps)
+		ret = self._highest_pkg_cache.get(cache_key)
+		if ret is not None:
+			pkg, existing = ret
+			if pkg and not existing:
+				existing = self._slot_pkg_map[root].get(pkg.slot_atom)
+				if existing and existing == pkg:
+					# Update the cache to reflect that the
+					# package has been added to the graph.
+					ret = pkg, pkg
+					self._highest_pkg_cache[cache_key] = ret
+			return ret
+		ret = self._select_pkg_highest_available_imp(root, atom, onlydeps=onlydeps)
+		self._highest_pkg_cache[cache_key] = ret
+		pkg, existing = ret
+		if pkg is not None:
+			settings = pkg.root_config.settings
+			if visible(settings, pkg) and not (pkg.installed and \
+				settings._getMissingKeywords(pkg.cpv, pkg.metadata)):
+				pkg.root_config.visible_pkgs.cpv_inject(pkg)
+		return ret
+
+	def _select_pkg_highest_available_imp(self, root, atom, onlydeps=False):
+		root_config = self.roots[root]
+		pkgsettings = self.pkgsettings[root]
+		dbs = self._filtered_trees[root]["dbs"]
+		vardb = self.roots[root].trees["vartree"].dbapi
+		portdb = self.roots[root].trees["porttree"].dbapi
+		# List of acceptable packages, ordered by type preference.
+		matched_packages = []
+		highest_version = None
+		if not isinstance(atom, portage.dep.Atom):
+			atom = portage.dep.Atom(atom)
+		atom_cp = atom.cp
+		atom_set = InternalPackageSet(initial_atoms=(atom,))
+		existing_node = None
+		myeb = None
+		usepkgonly = "--usepkgonly" in self.myopts
+		empty = "empty" in self.myparams
+		selective = "selective" in self.myparams
+		reinstall = False
+		noreplace = "--noreplace" in self.myopts
+		# Behavior of the "selective" parameter depends on
+		# whether or not a package matches an argument atom.
+		# If an installed package provides an old-style
+		# virtual that is no longer provided by an available
+		# package, the installed package may match an argument
+		# atom even though none of the available packages do.
+		# Therefore, "selective" logic does not consider
+		# whether or not an installed package matches an
+		# argument atom. It only considers whether or not
+		# available packages match argument atoms, which is
+		# represented by the found_available_arg flag.
+		found_available_arg = False
+		for find_existing_node in True, False:
+			if existing_node:
+				break
+			for db, pkg_type, built, installed, db_keys in dbs:
+				if existing_node:
+					break
+				if installed and not find_existing_node:
+					want_reinstall = reinstall or empty or \
+						(found_available_arg and not selective)
+					if want_reinstall and matched_packages:
+						continue
+				if hasattr(db, "xmatch"):
+					cpv_list = db.xmatch("match-all", atom)
+				else:
+					cpv_list = db.match(atom)
+
+				# USE=multislot can make an installed package appear as if
+				# it doesn't satisfy a slot dependency. Rebuilding the ebuild
+				# won't do any good as long as USE=multislot is enabled since
+				# the newly built package still won't have the expected slot.
+				# Therefore, assume that such SLOT dependencies are already
+				# satisfied rather than forcing a rebuild.
+				if installed and not cpv_list and atom.slot:
+					for cpv in db.match(atom.cp):
+						slot_available = False
+						for other_db, other_type, other_built, \
+							other_installed, other_keys in dbs:
+							try:
+								if atom.slot == \
+									other_db.aux_get(cpv, ["SLOT"])[0]:
+									slot_available = True
+									break
+							except KeyError:
+								pass
+						if not slot_available:
+							continue
+						inst_pkg = self._pkg(cpv, "installed",
+							root_config, installed=installed)
+						# Remove the slot from the atom and verify that
+						# the package matches the resulting atom.
+						atom_without_slot = portage.dep.remove_slot(atom)
+						if atom.use:
+							atom_without_slot += str(atom.use)
+						atom_without_slot = portage.dep.Atom(atom_without_slot)
+						if portage.match_from_list(
+							atom_without_slot, [inst_pkg]):
+							cpv_list = [inst_pkg.cpv]
+						break
+
+				if not cpv_list:
+					continue
+				pkg_status = "merge"
+				if installed or onlydeps:
+					pkg_status = "nomerge"
+				# descending order
+				cpv_list.reverse()
+				for cpv in cpv_list:
+					# Make --noreplace take precedence over --newuse.
+					if not installed and noreplace and \
+						cpv in vardb.match(atom):
+						# If the installed version is masked, it may
+						# be necessary to look at lower versions,
+						# in case there is a visible downgrade.
+						continue
+					reinstall_for_flags = None
+					cache_key = (pkg_type, root, cpv, pkg_status)
+					calculated_use = True
+					pkg = self._pkg_cache.get(cache_key)
+					if pkg is None:
+						calculated_use = False
+						try:
+							metadata = izip(db_keys, db.aux_get(cpv, db_keys))
+						except KeyError:
+							continue
+						pkg = Package(built=built, cpv=cpv,
+							installed=installed, metadata=metadata,
+							onlydeps=onlydeps, root_config=root_config,
+							type_name=pkg_type)
+						metadata = pkg.metadata
+						if not built:
+							metadata['CHOST'] = pkgsettings.get('CHOST', '')
+						if not built and ("?" in metadata["LICENSE"] or \
+							"?" in metadata["PROVIDE"]):
+							# This is avoided whenever possible because
+							# it's expensive. It only needs to be done here
+							# if it has an effect on visibility.
+							pkgsettings.setcpv(pkg)
+							metadata["USE"] = pkgsettings["PORTAGE_USE"]
+							calculated_use = True
+						self._pkg_cache[pkg] = pkg
+
+					if not installed or (built and matched_packages):
+						# Only enforce visibility on installed packages
+						# if there is at least one other visible package
+						# available. By filtering installed masked packages
+						# here, packages that have been masked since they
+						# were installed can be automatically downgraded
+						# to an unmasked version.
+						try:
+							if not visible(pkgsettings, pkg):
+								continue
+						except portage.exception.InvalidDependString:
+							if not installed:
+								continue
+
+						# Enable upgrade or downgrade to a version
+						# with visible KEYWORDS when the installed
+						# version is masked by KEYWORDS, but never
+						# reinstall the same exact version only due
+						# to a KEYWORDS mask.
+						if built and matched_packages:
+
+							different_version = None
+							for avail_pkg in matched_packages:
+								if not portage.dep.cpvequal(
+									pkg.cpv, avail_pkg.cpv):
+									different_version = avail_pkg
+									break
+							if different_version is not None:
+
+								if installed and \
+									pkgsettings._getMissingKeywords(
+									pkg.cpv, pkg.metadata):
+									continue
+
+								# If the ebuild no longer exists or it's
+								# keywords have been dropped, reject built
+								# instances (installed or binary).
+								# If --usepkgonly is enabled, assume that
+								# the ebuild status should be ignored.
+								if not usepkgonly:
+									try:
+										pkg_eb = self._pkg(
+											pkg.cpv, "ebuild", root_config)
+									except portage.exception.PackageNotFound:
+										continue
+									else:
+										if not visible(pkgsettings, pkg_eb):
+											continue
+
+					if not pkg.built and not calculated_use:
+						# This is avoided whenever possible because
+						# it's expensive.
+						pkgsettings.setcpv(pkg)
+						pkg.metadata["USE"] = pkgsettings["PORTAGE_USE"]
+
+					if pkg.cp != atom.cp:
+						# A cpv can be returned from dbapi.match() as an
+						# old-style virtual match even in cases when the
+						# package does not actually PROVIDE the virtual.
+						# Filter out any such false matches here.
+						if not atom_set.findAtomForPackage(pkg):
+							continue
+
+					myarg = None
+					if root == self.target_root:
+						try:
+							# Ebuild USE must have been calculated prior
+							# to this point, in case atoms have USE deps.
+							myarg = self._iter_atoms_for_pkg(pkg).next()
+						except StopIteration:
+							pass
+						except portage.exception.InvalidDependString:
+							if not installed:
+								# masked by corruption
+								continue
+					if not installed and myarg:
+						found_available_arg = True
+
+					if atom.use and not pkg.built:
+						use = pkg.use.enabled
+						if atom.use.enabled.difference(use):
+							continue
+						if atom.use.disabled.intersection(use):
+							continue
+					if pkg.cp == atom_cp:
+						if highest_version is None:
+							highest_version = pkg
+						elif pkg > highest_version:
+							highest_version = pkg
+					# At this point, we've found the highest visible
+					# match from the current repo. Any lower versions
+					# from this repo are ignored, so this so the loop
+					# will always end with a break statement below
+					# this point.
+					if find_existing_node:
+						e_pkg = self._slot_pkg_map[root].get(pkg.slot_atom)
+						if not e_pkg:
+							break
+						if portage.dep.match_from_list(atom, [e_pkg]):
+							if highest_version and \
+								e_pkg.cp == atom_cp and \
+								e_pkg < highest_version and \
+								e_pkg.slot_atom != highest_version.slot_atom:
+								# There is a higher version available in a
+								# different slot, so this existing node is
+								# irrelevant.
+								pass
+							else:
+								matched_packages.append(e_pkg)
+								existing_node = e_pkg
+						break
+					# Compare built package to current config and
+					# reject the built package if necessary.
+					if built and not installed and \
+						("--newuse" in self.myopts or \
+						"--reinstall" in self.myopts):
+						iuses = pkg.iuse.all
+						old_use = pkg.use.enabled
+						if myeb:
+							pkgsettings.setcpv(myeb)
+						else:
+							pkgsettings.setcpv(pkg)
+						now_use = pkgsettings["PORTAGE_USE"].split()
+						forced_flags = set()
+						forced_flags.update(pkgsettings.useforce)
+						forced_flags.update(pkgsettings.usemask)
+						cur_iuse = iuses
+						if myeb and not usepkgonly:
+							cur_iuse = myeb.iuse.all
+						if self._reinstall_for_flags(forced_flags,
+							old_use, iuses,
+							now_use, cur_iuse):
+							break
+					# Compare current config to installed package
+					# and do not reinstall if possible.
+					if not installed and \
+						("--newuse" in self.myopts or \
+						"--reinstall" in self.myopts) and \
+						cpv in vardb.match(atom):
+						pkgsettings.setcpv(pkg)
+						forced_flags = set()
+						forced_flags.update(pkgsettings.useforce)
+						forced_flags.update(pkgsettings.usemask)
+						old_use = vardb.aux_get(cpv, ["USE"])[0].split()
+						old_iuse = set(filter_iuse_defaults(
+							vardb.aux_get(cpv, ["IUSE"])[0].split()))
+						cur_use = pkg.use.enabled
+						cur_iuse = pkg.iuse.all
+						reinstall_for_flags = \
+							self._reinstall_for_flags(
+							forced_flags, old_use, old_iuse,
+							cur_use, cur_iuse)
+						if reinstall_for_flags:
+							reinstall = True
+					if not built:
+						myeb = pkg
+					matched_packages.append(pkg)
+					if reinstall_for_flags:
+						self._reinstall_nodes[pkg] = \
+							reinstall_for_flags
+					break
+
+		if not matched_packages:
+			return None, None
+
+		if "--debug" in self.myopts:
+			for pkg in matched_packages:
+				portage.writemsg("%s %s\n" % \
+					((pkg.type_name + ":").rjust(10), pkg.cpv), noiselevel=-1)
+
+		# Filter out any old-style virtual matches if they are
+		# mixed with new-style virtual matches.
+		cp = portage.dep_getkey(atom)
+		if len(matched_packages) > 1 and \
+			"virtual" == portage.catsplit(cp)[0]:
+			for pkg in matched_packages:
+				if pkg.cp != cp:
+					continue
+				# Got a new-style virtual, so filter
+				# out any old-style virtuals.
+				matched_packages = [pkg for pkg in matched_packages \
+					if pkg.cp == cp]
+				break
+
+		if len(matched_packages) > 1:
+			bestmatch = portage.best(
+				[pkg.cpv for pkg in matched_packages])
+			matched_packages = [pkg for pkg in matched_packages \
+				if portage.dep.cpvequal(pkg.cpv, bestmatch)]
+
+		# ordered by type preference ("ebuild" type is the last resort)
+		return  matched_packages[-1], existing_node
+
+	def _select_pkg_from_graph(self, root, atom, onlydeps=False):
+		"""
+		Select packages that have already been added to the graph or
+		those that are installed and have not been scheduled for
+		replacement.
+		"""
+		graph_db = self._graph_trees[root]["porttree"].dbapi
+		matches = graph_db.match_pkgs(atom)
+		if not matches:
+			return None, None
+		pkg = matches[-1] # highest match
+		in_graph = self._slot_pkg_map[root].get(pkg.slot_atom)
+		return pkg, in_graph
+
+	def _complete_graph(self):
+		"""
+		Add any deep dependencies of required sets (args, system, world) that
+		have not been pulled into the graph yet. This ensures that the graph
+		is consistent such that initially satisfied deep dependencies are not
+		broken in the new graph. Initially unsatisfied dependencies are
+		irrelevant since we only want to avoid breaking dependencies that are
+		intially satisfied.
+
+		Since this method can consume enough time to disturb users, it is
+		currently only enabled by the --complete-graph option.
+		"""
+		if "--buildpkgonly" in self.myopts or \
+			"recurse" not in self.myparams:
+			return 1
+
+		if "complete" not in self.myparams:
+			# Skip this to avoid consuming enough time to disturb users.
+			return 1
+
+		# Put the depgraph into a mode that causes it to only
+		# select packages that have already been added to the
+		# graph or those that are installed and have not been
+		# scheduled for replacement. Also, toggle the "deep"
+		# parameter so that all dependencies are traversed and
+		# accounted for.
+		self._select_atoms = self._select_atoms_from_graph
+		self._select_package = self._select_pkg_from_graph
+		already_deep = "deep" in self.myparams
+		if not already_deep:
+			self.myparams.add("deep")
+
+		for root in self.roots:
+			required_set_names = self._required_set_names.copy()
+			if root == self.target_root and \
+				(already_deep or "empty" in self.myparams):
+				required_set_names.difference_update(self._sets)
+			if not required_set_names and not self._ignored_deps:
+				continue
+			root_config = self.roots[root]
+			setconfig = root_config.setconfig
+			args = []
+			# Reuse existing SetArg instances when available.
+			for arg in self.digraph.root_nodes():
+				if not isinstance(arg, SetArg):
+					continue
+				if arg.root_config != root_config:
+					continue
+				if arg.name in required_set_names:
+					args.append(arg)
+					required_set_names.remove(arg.name)
+			# Create new SetArg instances only when necessary.
+			for s in required_set_names:
+				expanded_set = InternalPackageSet(
+					initial_atoms=setconfig.getSetAtoms(s))
+				atom = SETPREFIX + s
+				args.append(SetArg(arg=atom, set=expanded_set,
+					root_config=root_config))
+			vardb = root_config.trees["vartree"].dbapi
+			for arg in args:
+				for atom in arg.set:
+					self._dep_stack.append(
+						Dependency(atom=atom, root=root, parent=arg))
+			if self._ignored_deps:
+				self._dep_stack.extend(self._ignored_deps)
+				self._ignored_deps = []
+			if not self._create_graph(allow_unsatisfied=True):
+				return 0
+			# Check the unsatisfied deps to see if any initially satisfied deps
+			# will become unsatisfied due to an upgrade. Initially unsatisfied
+			# deps are irrelevant since we only want to avoid breaking deps
+			# that are initially satisfied.
+			while self._unsatisfied_deps:
+				dep = self._unsatisfied_deps.pop()
+				matches = vardb.match_pkgs(dep.atom)
+				if not matches:
+					self._initially_unsatisfied_deps.append(dep)
+					continue
+				# An scheduled installation broke a deep dependency.
+				# Add the installed package to the graph so that it
+				# will be appropriately reported as a slot collision
+				# (possibly solvable via backtracking).
+				pkg = matches[-1] # highest match
+				if not self._add_pkg(pkg, dep):
+					return 0
+				if not self._create_graph(allow_unsatisfied=True):
+					return 0
+		return 1
+
+	def _pkg(self, cpv, type_name, root_config, installed=False):
+		"""
+		Get a package instance from the cache, or create a new
+		one if necessary. Raises KeyError from aux_get if it
+		failures for some reason (package does not exist or is
+		corrupt).
+		"""
+		operation = "merge"
+		if installed:
+			operation = "nomerge"
+		pkg = self._pkg_cache.get(
+			(type_name, root_config.root, cpv, operation))
+		if pkg is None:
+			tree_type = self.pkg_tree_map[type_name]
+			db = root_config.trees[tree_type].dbapi
+			db_keys = list(self._trees_orig[root_config.root][
+				tree_type].dbapi._aux_cache_keys)
+			try:
+				metadata = izip(db_keys, db.aux_get(cpv, db_keys))
+			except KeyError:
+				raise portage.exception.PackageNotFound(cpv)
+			pkg = Package(cpv=cpv, metadata=metadata,
+				root_config=root_config, installed=installed)
+			if type_name == "ebuild":
+				settings = self.pkgsettings[root_config.root]
+				settings.setcpv(pkg)
+				pkg.metadata["USE"] = settings["PORTAGE_USE"]
+				pkg.metadata['CHOST'] = settings.get('CHOST', '')
+			self._pkg_cache[pkg] = pkg
+		return pkg
+
+	def validate_blockers(self):
+		"""Remove any blockers from the digraph that do not match any of the
+		packages within the graph.  If necessary, create hard deps to ensure
+		correct merge order such that mutually blocking packages are never
+		installed simultaneously."""
+
+		if "--buildpkgonly" in self.myopts or \
+			"--nodeps" in self.myopts:
+			return True
+
+		#if "deep" in self.myparams:
+		if True:
+			# Pull in blockers from all installed packages that haven't already
+			# been pulled into the depgraph.  This is not enabled by default
+			# due to the performance penalty that is incurred by all the
+			# additional dep_check calls that are required.
+
+			dep_keys = ["DEPEND","RDEPEND","PDEPEND"]
+			for myroot in self.trees:
+				vardb = self.trees[myroot]["vartree"].dbapi
+				portdb = self.trees[myroot]["porttree"].dbapi
+				pkgsettings = self.pkgsettings[myroot]
+				final_db = self.mydbapi[myroot]
+
+				blocker_cache = BlockerCache(myroot, vardb)
+				stale_cache = set(blocker_cache)
+				for pkg in vardb:
+					cpv = pkg.cpv
+					stale_cache.discard(cpv)
+					pkg_in_graph = self.digraph.contains(pkg)
+
+					# Check for masked installed packages. Only warn about
+					# packages that are in the graph in order to avoid warning
+					# about those that will be automatically uninstalled during
+					# the merge process or by --depclean.
+					if pkg in final_db:
+						if pkg_in_graph and not visible(pkgsettings, pkg):
+							self._masked_installed.add(pkg)
+
+					blocker_atoms = None
+					blockers = None
+					if pkg_in_graph:
+						blockers = []
+						try:
+							blockers.extend(
+								self._blocker_parents.child_nodes(pkg))
+						except KeyError:
+							pass
+						try:
+							blockers.extend(
+								self._irrelevant_blockers.child_nodes(pkg))
+						except KeyError:
+							pass
+					if blockers is not None:
+						blockers = set(str(blocker.atom) \
+							for blocker in blockers)
+
+					# If this node has any blockers, create a "nomerge"
+					# node for it so that they can be enforced.
+					self.spinner.update()
+					blocker_data = blocker_cache.get(cpv)
+					if blocker_data is not None and \
+						blocker_data.counter != long(pkg.metadata["COUNTER"]):
+						blocker_data = None
+
+					# If blocker data from the graph is available, use
+					# it to validate the cache and update the cache if
+					# it seems invalid.
+					if blocker_data is not None and \
+						blockers is not None:
+						if not blockers.symmetric_difference(
+							blocker_data.atoms):
+							continue
+						blocker_data = None
+
+					if blocker_data is None and \
+						blockers is not None:
+						# Re-use the blockers from the graph.
+						blocker_atoms = sorted(blockers)
+						counter = long(pkg.metadata["COUNTER"])
+						blocker_data = \
+							blocker_cache.BlockerData(counter, blocker_atoms)
+						blocker_cache[pkg.cpv] = blocker_data
+						continue
+
+					if blocker_data:
+						blocker_atoms = blocker_data.atoms
+					else:
+						# Use aux_get() to trigger FakeVartree global
+						# updates on *DEPEND when appropriate.
+						depstr = " ".join(vardb.aux_get(pkg.cpv, dep_keys))
+						# It is crucial to pass in final_db here in order to
+						# optimize dep_check calls by eliminating atoms via
+						# dep_wordreduce and dep_eval calls.
+						try:
+							portage.dep._dep_check_strict = False
+							try:
+								success, atoms = portage.dep_check(depstr,
+									final_db, pkgsettings, myuse=pkg.use.enabled,
+									trees=self._graph_trees, myroot=myroot)
+							except Exception, e:
+								if isinstance(e, SystemExit):
+									raise
+								# This is helpful, for example, if a ValueError
+								# is thrown from cpv_expand due to multiple
+								# matches (this can happen if an atom lacks a
+								# category).
+								show_invalid_depstring_notice(
+									pkg, depstr, str(e))
+								del e
+								raise
+						finally:
+							portage.dep._dep_check_strict = True
+						if not success:
+							replacement_pkg = final_db.match_pkgs(pkg.slot_atom)
+							if replacement_pkg and \
+								replacement_pkg[0].operation == "merge":
+								# This package is being replaced anyway, so
+								# ignore invalid dependencies so as not to
+								# annoy the user too much (otherwise they'd be
+								# forced to manually unmerge it first).
+								continue
+							show_invalid_depstring_notice(pkg, depstr, atoms)
+							return False
+						blocker_atoms = [myatom for myatom in atoms \
+							if myatom.startswith("!")]
+						blocker_atoms.sort()
+						counter = long(pkg.metadata["COUNTER"])
+						blocker_cache[cpv] = \
+							blocker_cache.BlockerData(counter, blocker_atoms)
+					if blocker_atoms:
+						try:
+							for atom in blocker_atoms:
+								blocker = Blocker(atom=portage.dep.Atom(atom),
+									eapi=pkg.metadata["EAPI"], root=myroot)
+								self._blocker_parents.add(blocker, pkg)
+						except portage.exception.InvalidAtom, e:
+							depstr = " ".join(vardb.aux_get(pkg.cpv, dep_keys))
+							show_invalid_depstring_notice(
+								pkg, depstr, "Invalid Atom: %s" % (e,))
+							return False
+				for cpv in stale_cache:
+					del blocker_cache[cpv]
+				blocker_cache.flush()
+				del blocker_cache
+
+		# Discard any "uninstall" tasks scheduled by previous calls
+		# to this method, since those tasks may not make sense given
+		# the current graph state.
+		previous_uninstall_tasks = self._blocker_uninstalls.leaf_nodes()
+		if previous_uninstall_tasks:
+			self._blocker_uninstalls = digraph()
+			self.digraph.difference_update(previous_uninstall_tasks)
+
+		for blocker in self._blocker_parents.leaf_nodes():
+			self.spinner.update()
+			root_config = self.roots[blocker.root]
+			virtuals = root_config.settings.getvirtuals()
+			myroot = blocker.root
+			initial_db = self.trees[myroot]["vartree"].dbapi
+			final_db = self.mydbapi[myroot]
+			
+			provider_virtual = False
+			if blocker.cp in virtuals and \
+				not self._have_new_virt(blocker.root, blocker.cp):
+				provider_virtual = True
+
+			# Use this to check PROVIDE for each matched package
+			# when necessary.
+			atom_set = InternalPackageSet(
+				initial_atoms=[blocker.atom])
+
+			if provider_virtual:
+				atoms = []
+				for provider_entry in virtuals[blocker.cp]:
+					provider_cp = \
+						portage.dep_getkey(provider_entry)
+					atoms.append(blocker.atom.replace(
+						blocker.cp, provider_cp))
+			else:
+				atoms = [blocker.atom]
+
+			blocked_initial = set()
+			for atom in atoms:
+				for pkg in initial_db.match_pkgs(atom):
+					if atom_set.findAtomForPackage(pkg):
+						blocked_initial.add(pkg)
+
+			blocked_final = set()
+			for atom in atoms:
+				for pkg in final_db.match_pkgs(atom):
+					if atom_set.findAtomForPackage(pkg):
+						blocked_final.add(pkg)
+
+			if not blocked_initial and not blocked_final:
+				parent_pkgs = self._blocker_parents.parent_nodes(blocker)
+				self._blocker_parents.remove(blocker)
+				# Discard any parents that don't have any more blockers.
+				for pkg in parent_pkgs:
+					self._irrelevant_blockers.add(blocker, pkg)
+					if not self._blocker_parents.child_nodes(pkg):
+						self._blocker_parents.remove(pkg)
+				continue
+			for parent in self._blocker_parents.parent_nodes(blocker):
+				unresolved_blocks = False
+				depends_on_order = set()
+				for pkg in blocked_initial:
+					if pkg.slot_atom == parent.slot_atom:
+						# TODO: Support blocks within slots in cases where it
+						# might make sense.  For example, a new version might
+						# require that the old version be uninstalled at build
+						# time.
+						continue
+					if parent.installed:
+						# Two currently installed packages conflict with
+						# eachother. Ignore this case since the damage
+						# is already done and this would be likely to
+						# confuse users if displayed like a normal blocker.
+						continue
+
+					self._blocked_pkgs.add(pkg, blocker)
+
+					if parent.operation == "merge":
+						# Maybe the blocked package can be replaced or simply
+						# unmerged to resolve this block.
+						depends_on_order.add((pkg, parent))
+						continue
+					# None of the above blocker resolutions techniques apply,
+					# so apparently this one is unresolvable.
+					unresolved_blocks = True
+				for pkg in blocked_final:
+					if pkg.slot_atom == parent.slot_atom:
+						# TODO: Support blocks within slots.
+						continue
+					if parent.operation == "nomerge" and \
+						pkg.operation == "nomerge":
+						# This blocker will be handled the next time that a
+						# merge of either package is triggered.
+						continue
+
+					self._blocked_pkgs.add(pkg, blocker)
+
+					# Maybe the blocking package can be
+					# unmerged to resolve this block.
+					if parent.operation == "merge" and pkg.installed:
+						depends_on_order.add((pkg, parent))
+						continue
+					elif parent.operation == "nomerge":
+						depends_on_order.add((parent, pkg))
+						continue
+					# None of the above blocker resolutions techniques apply,
+					# so apparently this one is unresolvable.
+					unresolved_blocks = True
+
+				# Make sure we don't unmerge any package that have been pulled
+				# into the graph.
+				if not unresolved_blocks and depends_on_order:
+					for inst_pkg, inst_task in depends_on_order:
+						if self.digraph.contains(inst_pkg) and \
+							self.digraph.parent_nodes(inst_pkg):
+							unresolved_blocks = True
+							break
+
+				if not unresolved_blocks and depends_on_order:
+					for inst_pkg, inst_task in depends_on_order:
+						uninst_task = Package(built=inst_pkg.built,
+							cpv=inst_pkg.cpv, installed=inst_pkg.installed,
+							metadata=inst_pkg.metadata,
+							operation="uninstall",
+							root_config=inst_pkg.root_config,
+							type_name=inst_pkg.type_name)
+						self._pkg_cache[uninst_task] = uninst_task
+						# Enforce correct merge order with a hard dep.
+						self.digraph.addnode(uninst_task, inst_task,
+							priority=BlockerDepPriority.instance)
+						# Count references to this blocker so that it can be
+						# invalidated after nodes referencing it have been
+						# merged.
+						self._blocker_uninstalls.addnode(uninst_task, blocker)
+				if not unresolved_blocks and not depends_on_order:
+					self._irrelevant_blockers.add(blocker, parent)
+					self._blocker_parents.remove_edge(blocker, parent)
+					if not self._blocker_parents.parent_nodes(blocker):
+						self._blocker_parents.remove(blocker)
+					if not self._blocker_parents.child_nodes(parent):
+						self._blocker_parents.remove(parent)
+				if unresolved_blocks:
+					self._unsolvable_blockers.add(blocker, parent)
+
+		return True
+
+	def _accept_blocker_conflicts(self):
+		acceptable = False
+		for x in ("--buildpkgonly", "--fetchonly",
+			"--fetch-all-uri", "--nodeps"):
+			if x in self.myopts:
+				acceptable = True
+				break
+		return acceptable
+
+	def _merge_order_bias(self, mygraph):
+		"""
+		For optimal leaf node selection, promote deep system runtime deps and
+		order nodes from highest to lowest overall reference count.
+		"""
+
+		node_info = {}
+		for node in mygraph.order:
+			node_info[node] = len(mygraph.parent_nodes(node))
+		deep_system_deps = _find_deep_system_runtime_deps(mygraph)
+
+		def cmp_merge_preference(node1, node2):
+
+			if node1.operation == 'uninstall':
+				if node2.operation == 'uninstall':
+					return 0
+				return 1
+
+			if node2.operation == 'uninstall':
+				if node1.operation == 'uninstall':
+					return 0
+				return -1
+
+			node1_sys = node1 in deep_system_deps
+			node2_sys = node2 in deep_system_deps
+			if node1_sys != node2_sys:
+				if node1_sys:
+					return -1
+				return 1
+
+			return node_info[node2] - node_info[node1]
+
+		mygraph.order.sort(key=cmp_sort_key(cmp_merge_preference))
+
+	def altlist(self, reversed=False):
+
+		while self._serialized_tasks_cache is None:
+			self._resolve_conflicts()
+			try:
+				self._serialized_tasks_cache, self._scheduler_graph = \
+					self._serialize_tasks()
+			except self._serialize_tasks_retry:
+				pass
+
+		retlist = self._serialized_tasks_cache[:]
+		if reversed:
+			retlist.reverse()
+		return retlist
+
+	def schedulerGraph(self):
+		"""
+		The scheduler graph is identical to the normal one except that
+		uninstall edges are reversed in specific cases that require
+		conflicting packages to be temporarily installed simultaneously.
+		This is intended for use by the Scheduler in it's parallelization
+		logic. It ensures that temporary simultaneous installation of
+		conflicting packages is avoided when appropriate (especially for
+		!!atom blockers), but allowed in specific cases that require it.
+
+		Note that this method calls break_refs() which alters the state of
+		internal Package instances such that this depgraph instance should
+		not be used to perform any more calculations.
+		"""
+		if self._scheduler_graph is None:
+			self.altlist()
+		self.break_refs(self._scheduler_graph.order)
+		return self._scheduler_graph
+
+	def break_refs(self, nodes):
+		"""
+		Take a mergelist like that returned from self.altlist() and
+		break any references that lead back to the depgraph. This is
+		useful if you want to hold references to packages without
+		also holding the depgraph on the heap.
+		"""
+		for node in nodes:
+			if hasattr(node, "root_config"):
+				# The FakeVartree references the _package_cache which
+				# references the depgraph. So that Package instances don't
+				# hold the depgraph and FakeVartree on the heap, replace
+				# the RootConfig that references the FakeVartree with the
+				# original RootConfig instance which references the actual
+				# vartree.
+				node.root_config = \
+					self._trees_orig[node.root_config.root]["root_config"]
+
+	def _resolve_conflicts(self):
+		if not self._complete_graph():
+			raise self._unknown_internal_error()
+
+		if not self.validate_blockers():
+			raise self._unknown_internal_error()
+
+		if self._slot_collision_info:
+			self._process_slot_conflicts()
+
+	def _serialize_tasks(self):
+
+		if "--debug" in self.myopts:
+			writemsg("\ndigraph:\n\n", noiselevel=-1)
+			self.digraph.debug_print()
+			writemsg("\n", noiselevel=-1)
+
+		scheduler_graph = self.digraph.copy()
+
+		if '--nodeps' in self.myopts:
+			# Preserve the package order given on the command line.
+			return ([node for node in scheduler_graph \
+				if isinstance(node, Package) \
+				and node.operation == 'merge'], scheduler_graph)
+
+		mygraph=self.digraph.copy()
+		# Prune "nomerge" root nodes if nothing depends on them, since
+		# otherwise they slow down merge order calculation. Don't remove
+		# non-root nodes since they help optimize merge order in some cases
+		# such as revdep-rebuild.
+		removed_nodes = set()
+		while True:
+			for node in mygraph.root_nodes():
+				if not isinstance(node, Package) or \
+					node.installed or node.onlydeps:
+					removed_nodes.add(node)
+			if removed_nodes:
+				self.spinner.update()
+				mygraph.difference_update(removed_nodes)
+			if not removed_nodes:
+				break
+			removed_nodes.clear()
+		self._merge_order_bias(mygraph)
+		def cmp_circular_bias(n1, n2):
+			"""
+			RDEPEND is stronger than PDEPEND and this function
+			measures such a strength bias within a circular
+			dependency relationship.
+			"""
+			n1_n2_medium = n2 in mygraph.child_nodes(n1,
+				ignore_priority=priority_range.ignore_medium_soft)
+			n2_n1_medium = n1 in mygraph.child_nodes(n2,
+				ignore_priority=priority_range.ignore_medium_soft)
+			if n1_n2_medium == n2_n1_medium:
+				return 0
+			elif n1_n2_medium:
+				return 1
+			return -1
+		myblocker_uninstalls = self._blocker_uninstalls.copy()
+		retlist=[]
+		# Contains uninstall tasks that have been scheduled to
+		# occur after overlapping blockers have been installed.
+		scheduled_uninstalls = set()
+		# Contains any Uninstall tasks that have been ignored
+		# in order to avoid the circular deps code path. These
+		# correspond to blocker conflicts that could not be
+		# resolved.
+		ignored_uninstall_tasks = set()
+		have_uninstall_task = False
+		complete = "complete" in self.myparams
+		asap_nodes = []
+
+		def get_nodes(**kwargs):
+			"""
+			Returns leaf nodes excluding Uninstall instances
+			since those should be executed as late as possible.
+			"""
+			return [node for node in mygraph.leaf_nodes(**kwargs) \
+				if isinstance(node, Package) and \
+					(node.operation != "uninstall" or \
+					node in scheduled_uninstalls)]
+
+		# sys-apps/portage needs special treatment if ROOT="/"
+		running_root = self._running_root.root
+		from portage.const import PORTAGE_PACKAGE_ATOM
+		runtime_deps = InternalPackageSet(
+			initial_atoms=[PORTAGE_PACKAGE_ATOM])
+		running_portage = self.trees[running_root]["vartree"].dbapi.match_pkgs(
+			PORTAGE_PACKAGE_ATOM)
+		replacement_portage = self.mydbapi[running_root].match_pkgs(
+			PORTAGE_PACKAGE_ATOM)
+
+		if running_portage:
+			running_portage = running_portage[0]
+		else:
+			running_portage = None
+
+		if replacement_portage:
+			replacement_portage = replacement_portage[0]
+		else:
+			replacement_portage = None
+
+		if replacement_portage == running_portage:
+			replacement_portage = None
+
+		if replacement_portage is not None:
+			# update from running_portage to replacement_portage asap
+			asap_nodes.append(replacement_portage)
+
+		if running_portage is not None:
+			try:
+				portage_rdepend = self._select_atoms_highest_available(
+					running_root, running_portage.metadata["RDEPEND"],
+					myuse=running_portage.use.enabled,
+					parent=running_portage, strict=False)
+			except portage.exception.InvalidDependString, e:
+				portage.writemsg("!!! Invalid RDEPEND in " + \
+					"'%svar/db/pkg/%s/RDEPEND': %s\n" % \
+					(running_root, running_portage.cpv, e), noiselevel=-1)
+				del e
+				portage_rdepend = []
+			runtime_deps.update(atom for atom in portage_rdepend \
+				if not atom.startswith("!"))
+
+		def gather_deps(ignore_priority, mergeable_nodes,
+			selected_nodes, node):
+			"""
+			Recursively gather a group of nodes that RDEPEND on
+			eachother. This ensures that they are merged as a group
+			and get their RDEPENDs satisfied as soon as possible.
+			"""
+			if node in selected_nodes:
+				return True
+			if node not in mergeable_nodes:
+				return False
+			if node == replacement_portage and \
+				mygraph.child_nodes(node,
+				ignore_priority=priority_range.ignore_medium_soft):
+				# Make sure that portage always has all of it's
+				# RDEPENDs installed first.
+				return False
+			selected_nodes.add(node)
+			for child in mygraph.child_nodes(node,
+				ignore_priority=ignore_priority):
+				if not gather_deps(ignore_priority,
+					mergeable_nodes, selected_nodes, child):
+					return False
+			return True
+
+		def ignore_uninst_or_med(priority):
+			if priority is BlockerDepPriority.instance:
+				return True
+			return priority_range.ignore_medium(priority)
+
+		def ignore_uninst_or_med_soft(priority):
+			if priority is BlockerDepPriority.instance:
+				return True
+			return priority_range.ignore_medium_soft(priority)
+
+		tree_mode = "--tree" in self.myopts
+		# Tracks whether or not the current iteration should prefer asap_nodes
+		# if available.  This is set to False when the previous iteration
+		# failed to select any nodes.  It is reset whenever nodes are
+		# successfully selected.
+		prefer_asap = True
+
+		# Controls whether or not the current iteration should drop edges that
+		# are "satisfied" by installed packages, in order to solve circular
+		# dependencies. The deep runtime dependencies of installed packages are
+		# not checked in this case (bug #199856), so it must be avoided
+		# whenever possible.
+		drop_satisfied = False
+
+		# State of variables for successive iterations that loosen the
+		# criteria for node selection.
+		#
+		# iteration   prefer_asap   drop_satisfied
+		# 1           True          False
+		# 2           False         False
+		# 3           False         True
+		#
+		# If no nodes are selected on the last iteration, it is due to
+		# unresolved blockers or circular dependencies.
+
+		while not mygraph.empty():
+			self.spinner.update()
+			selected_nodes = None
+			ignore_priority = None
+			if drop_satisfied or (prefer_asap and asap_nodes):
+				priority_range = DepPrioritySatisfiedRange
+			else:
+				priority_range = DepPriorityNormalRange
+			if prefer_asap and asap_nodes:
+				# ASAP nodes are merged before their soft deps. Go ahead and
+				# select root nodes here if necessary, since it's typical for
+				# the parent to have been removed from the graph already.
+				asap_nodes = [node for node in asap_nodes \
+					if mygraph.contains(node)]
+				for node in asap_nodes:
+					if not mygraph.child_nodes(node,
+						ignore_priority=priority_range.ignore_soft):
+						selected_nodes = [node]
+						asap_nodes.remove(node)
+						break
+			if not selected_nodes and \
+				not (prefer_asap and asap_nodes):
+				for i in xrange(priority_range.NONE,
+					priority_range.MEDIUM_SOFT + 1):
+					ignore_priority = priority_range.ignore_priority[i]
+					nodes = get_nodes(ignore_priority=ignore_priority)
+					if nodes:
+						# If there is a mix of uninstall nodes with other
+						# types, save the uninstall nodes for later since
+						# sometimes a merge node will render an uninstall
+						# node unnecessary (due to occupying the same slot),
+						# and we want to avoid executing a separate uninstall
+						# task in that case.
+						if len(nodes) > 1:
+							good_uninstalls = []
+							with_some_uninstalls_excluded = []
+							for node in nodes:
+								if node.operation == "uninstall":
+									slot_node = self.mydbapi[node.root
+										].match_pkgs(node.slot_atom)
+									if slot_node and \
+										slot_node[0].operation == "merge":
+										continue
+									good_uninstalls.append(node)
+								with_some_uninstalls_excluded.append(node)
+							if good_uninstalls:
+								nodes = good_uninstalls
+							elif with_some_uninstalls_excluded:
+								nodes = with_some_uninstalls_excluded
+							else:
+								nodes = nodes
+
+						if ignore_priority is None and not tree_mode:
+							# Greedily pop all of these nodes since no
+							# relationship has been ignored. This optimization
+							# destroys --tree output, so it's disabled in tree
+							# mode.
+							selected_nodes = nodes
+						else:
+							# For optimal merge order:
+							#  * Only pop one node.
+							#  * Removing a root node (node without a parent)
+							#    will not produce a leaf node, so avoid it.
+							#  * It's normal for a selected uninstall to be a
+							#    root node, so don't check them for parents.
+							for node in nodes:
+								if node.operation == "uninstall" or \
+									mygraph.parent_nodes(node):
+									selected_nodes = [node]
+									break
+
+						if selected_nodes:
+							break
+
+			if not selected_nodes:
+				nodes = get_nodes(ignore_priority=priority_range.ignore_medium)
+				if nodes:
+					mergeable_nodes = set(nodes)
+					if prefer_asap and asap_nodes:
+						nodes = asap_nodes
+					for i in xrange(priority_range.SOFT,
+						priority_range.MEDIUM_SOFT + 1):
+						ignore_priority = priority_range.ignore_priority[i]
+						for node in nodes:
+							if not mygraph.parent_nodes(node):
+								continue
+							selected_nodes = set()
+							if gather_deps(ignore_priority,
+								mergeable_nodes, selected_nodes, node):
+								break
+							else:
+								selected_nodes = None
+						if selected_nodes:
+							break
+
+					if prefer_asap and asap_nodes and not selected_nodes:
+						# We failed to find any asap nodes to merge, so ignore
+						# them for the next iteration.
+						prefer_asap = False
+						continue
+
+			if selected_nodes and ignore_priority is not None:
+				# Try to merge ignored medium_soft deps as soon as possible
+				# if they're not satisfied by installed packages.
+				for node in selected_nodes:
+					children = set(mygraph.child_nodes(node))
+					soft = children.difference(
+						mygraph.child_nodes(node,
+						ignore_priority=DepPrioritySatisfiedRange.ignore_soft))
+					medium_soft = children.difference(
+						mygraph.child_nodes(node,
+							ignore_priority = \
+							DepPrioritySatisfiedRange.ignore_medium_soft))
+					medium_soft.difference_update(soft)
+					for child in medium_soft:
+						if child in selected_nodes:
+							continue
+						if child in asap_nodes:
+							continue
+						asap_nodes.append(child)
+
+			if selected_nodes and len(selected_nodes) > 1:
+				if not isinstance(selected_nodes, list):
+					selected_nodes = list(selected_nodes)
+				selected_nodes.sort(key=cmp_sort_key(cmp_circular_bias))
+
+			if not selected_nodes and not myblocker_uninstalls.is_empty():
+				# An Uninstall task needs to be executed in order to
+				# avoid conflict if possible.
+
+				if drop_satisfied:
+					priority_range = DepPrioritySatisfiedRange
+				else:
+					priority_range = DepPriorityNormalRange
+
+				mergeable_nodes = get_nodes(
+					ignore_priority=ignore_uninst_or_med)
+
+				min_parent_deps = None
+				uninst_task = None
+				for task in myblocker_uninstalls.leaf_nodes():
+					# Do some sanity checks so that system or world packages
+					# don't get uninstalled inappropriately here (only really
+					# necessary when --complete-graph has not been enabled).
+
+					if task in ignored_uninstall_tasks:
+						continue
+
+					if task in scheduled_uninstalls:
+						# It's been scheduled but it hasn't
+						# been executed yet due to dependence
+						# on installation of blocking packages.
+						continue
+
+					root_config = self.roots[task.root]
+					inst_pkg = self._pkg_cache[
+						("installed", task.root, task.cpv, "nomerge")]
+
+					if self.digraph.contains(inst_pkg):
+						continue
+
+					forbid_overlap = False
+					heuristic_overlap = False
+					for blocker in myblocker_uninstalls.parent_nodes(task):
+						if blocker.eapi in ("0", "1"):
+							heuristic_overlap = True
+						elif blocker.atom.blocker.overlap.forbid:
+							forbid_overlap = True
+							break
+					if forbid_overlap and running_root == task.root:
+						continue
+
+					if heuristic_overlap and running_root == task.root:
+						# Never uninstall sys-apps/portage or it's essential
+						# dependencies, except through replacement.
+						try:
+							runtime_dep_atoms = \
+								list(runtime_deps.iterAtomsForPackage(task))
+						except portage.exception.InvalidDependString, e:
+							portage.writemsg("!!! Invalid PROVIDE in " + \
+								"'%svar/db/pkg/%s/PROVIDE': %s\n" % \
+								(task.root, task.cpv, e), noiselevel=-1)
+							del e
+							continue
+
+						# Don't uninstall a runtime dep if it appears
+						# to be the only suitable one installed.
+						skip = False
+						vardb = root_config.trees["vartree"].dbapi
+						for atom in runtime_dep_atoms:
+							other_version = None
+							for pkg in vardb.match_pkgs(atom):
+								if pkg.cpv == task.cpv and \
+									pkg.metadata["COUNTER"] == \
+									task.metadata["COUNTER"]:
+									continue
+								other_version = pkg
+								break
+							if other_version is None:
+								skip = True
+								break
+						if skip:
+							continue
+
+						# For packages in the system set, don't take
+						# any chances. If the conflict can't be resolved
+						# by a normal replacement operation then abort.
+						skip = False
+						try:
+							for atom in root_config.sets[
+								"system"].iterAtomsForPackage(task):
+								skip = True
+								break
+						except portage.exception.InvalidDependString, e:
+							portage.writemsg("!!! Invalid PROVIDE in " + \
+								"'%svar/db/pkg/%s/PROVIDE': %s\n" % \
+								(task.root, task.cpv, e), noiselevel=-1)
+							del e
+							skip = True
+						if skip:
+							continue
+
+					# Note that the world check isn't always
+					# necessary since self._complete_graph() will
+					# add all packages from the system and world sets to the
+					# graph. This just allows unresolved conflicts to be
+					# detected as early as possible, which makes it possible
+					# to avoid calling self._complete_graph() when it is
+					# unnecessary due to blockers triggering an abortion.
+					if not complete:
+						# For packages in the world set, go ahead an uninstall
+						# when necessary, as long as the atom will be satisfied
+						# in the final state.
+						graph_db = self.mydbapi[task.root]
+						skip = False
+						try:
+							for atom in root_config.sets[
+								"world"].iterAtomsForPackage(task):
+								satisfied = False
+								for pkg in graph_db.match_pkgs(atom):
+									if pkg == inst_pkg:
+										continue
+									satisfied = True
+									break
+								if not satisfied:
+									skip = True
+									self._blocked_world_pkgs[inst_pkg] = atom
+									break
+						except portage.exception.InvalidDependString, e:
+							portage.writemsg("!!! Invalid PROVIDE in " + \
+								"'%svar/db/pkg/%s/PROVIDE': %s\n" % \
+								(task.root, task.cpv, e), noiselevel=-1)
+							del e
+							skip = True
+						if skip:
+							continue
+
+					# Check the deps of parent nodes to ensure that
+					# the chosen task produces a leaf node. Maybe
+					# this can be optimized some more to make the
+					# best possible choice, but the current algorithm
+					# is simple and should be near optimal for most
+					# common cases.
+					mergeable_parent = False
+					parent_deps = set()
+					for parent in mygraph.parent_nodes(task):
+						parent_deps.update(mygraph.child_nodes(parent,
+							ignore_priority=priority_range.ignore_medium_soft))
+						if parent in mergeable_nodes and \
+							gather_deps(ignore_uninst_or_med_soft,
+							mergeable_nodes, set(), parent):
+							mergeable_parent = True
+
+					if not mergeable_parent:
+						continue
+
+					parent_deps.remove(task)
+					if min_parent_deps is None or \
+						len(parent_deps) < min_parent_deps:
+						min_parent_deps = len(parent_deps)
+						uninst_task = task
+
+				if uninst_task is not None:
+					# The uninstall is performed only after blocking
+					# packages have been merged on top of it. File
+					# collisions between blocking packages are detected
+					# and removed from the list of files to be uninstalled.
+					scheduled_uninstalls.add(uninst_task)
+					parent_nodes = mygraph.parent_nodes(uninst_task)
+
+					# Reverse the parent -> uninstall edges since we want
+					# to do the uninstall after blocking packages have
+					# been merged on top of it.
+					mygraph.remove(uninst_task)
+					for blocked_pkg in parent_nodes:
+						mygraph.add(blocked_pkg, uninst_task,
+							priority=BlockerDepPriority.instance)
+						scheduler_graph.remove_edge(uninst_task, blocked_pkg)
+						scheduler_graph.add(blocked_pkg, uninst_task,
+							priority=BlockerDepPriority.instance)
+
+					# Reset the state variables for leaf node selection and
+					# continue trying to select leaf nodes.
+					prefer_asap = True
+					drop_satisfied = False
+					continue
+
+			if not selected_nodes:
+				# Only select root nodes as a last resort. This case should
+				# only trigger when the graph is nearly empty and the only
+				# remaining nodes are isolated (no parents or children). Since
+				# the nodes must be isolated, ignore_priority is not needed.
+				selected_nodes = get_nodes()
+
+			if not selected_nodes and not drop_satisfied:
+				drop_satisfied = True
+				continue
+
+			if not selected_nodes and not myblocker_uninstalls.is_empty():
+				# If possible, drop an uninstall task here in order to avoid
+				# the circular deps code path. The corresponding blocker will
+				# still be counted as an unresolved conflict.
+				uninst_task = None
+				for node in myblocker_uninstalls.leaf_nodes():
+					try:
+						mygraph.remove(node)
+					except KeyError:
+						pass
+					else:
+						uninst_task = node
+						ignored_uninstall_tasks.add(node)
+						break
+
+				if uninst_task is not None:
+					# Reset the state variables for leaf node selection and
+					# continue trying to select leaf nodes.
+					prefer_asap = True
+					drop_satisfied = False
+					continue
+
+			if not selected_nodes:
+				self._circular_deps_for_display = mygraph
+				raise self._unknown_internal_error()
+
+			# At this point, we've succeeded in selecting one or more nodes, so
+			# reset state variables for leaf node selection.
+			prefer_asap = True
+			drop_satisfied = False
+
+			mygraph.difference_update(selected_nodes)
+
+			for node in selected_nodes:
+				if isinstance(node, Package) and \
+					node.operation == "nomerge":
+					continue
+
+				# Handle interactions between blockers
+				# and uninstallation tasks.
+				solved_blockers = set()
+				uninst_task = None
+				if isinstance(node, Package) and \
+					"uninstall" == node.operation:
+					have_uninstall_task = True
+					uninst_task = node
+				else:
+					vardb = self.trees[node.root]["vartree"].dbapi
+					previous_cpv = vardb.match(node.slot_atom)
+					if previous_cpv:
+						# The package will be replaced by this one, so remove
+						# the corresponding Uninstall task if necessary.
+						previous_cpv = previous_cpv[0]
+						uninst_task = \
+							("installed", node.root, previous_cpv, "uninstall")
+						try:
+							mygraph.remove(uninst_task)
+						except KeyError:
+							pass
+
+				if uninst_task is not None and \
+					uninst_task not in ignored_uninstall_tasks and \
+					myblocker_uninstalls.contains(uninst_task):
+					blocker_nodes = myblocker_uninstalls.parent_nodes(uninst_task)
+					myblocker_uninstalls.remove(uninst_task)
+					# Discard any blockers that this Uninstall solves.
+					for blocker in blocker_nodes:
+						if not myblocker_uninstalls.child_nodes(blocker):
+							myblocker_uninstalls.remove(blocker)
+							solved_blockers.add(blocker)
+
+				retlist.append(node)
+
+				if (isinstance(node, Package) and \
+					"uninstall" == node.operation) or \
+					(uninst_task is not None and \
+					uninst_task in scheduled_uninstalls):
+					# Include satisfied blockers in the merge list
+					# since the user might be interested and also
+					# it serves as an indicator that blocking packages
+					# will be temporarily installed simultaneously.
+					for blocker in solved_blockers:
+						retlist.append(Blocker(atom=blocker.atom,
+							root=blocker.root, eapi=blocker.eapi,
+							satisfied=True))
+
+		unsolvable_blockers = set(self._unsolvable_blockers.leaf_nodes())
+		for node in myblocker_uninstalls.root_nodes():
+			unsolvable_blockers.add(node)
+
+		for blocker in unsolvable_blockers:
+			retlist.append(blocker)
+
+		# If any Uninstall tasks need to be executed in order
+		# to avoid a conflict, complete the graph with any
+		# dependencies that may have been initially
+		# neglected (to ensure that unsafe Uninstall tasks
+		# are properly identified and blocked from execution).
+		if have_uninstall_task and \
+			not complete and \
+			not unsolvable_blockers:
+			self.myparams.add("complete")
+			raise self._serialize_tasks_retry("")
+
+		if unsolvable_blockers and \
+			not self._accept_blocker_conflicts():
+			self._unsatisfied_blockers_for_display = unsolvable_blockers
+			self._serialized_tasks_cache = retlist[:]
+			self._scheduler_graph = scheduler_graph
+			raise self._unknown_internal_error()
+
+		if self._slot_collision_info and \
+			not self._accept_blocker_conflicts():
+			self._serialized_tasks_cache = retlist[:]
+			self._scheduler_graph = scheduler_graph
+			raise self._unknown_internal_error()
+
+		return retlist, scheduler_graph
+
+	def _show_circular_deps(self, mygraph):
+		# No leaf nodes are available, so we have a circular
+		# dependency panic situation.  Reduce the noise level to a
+		# minimum via repeated elimination of root nodes since they
+		# have no parents and thus can not be part of a cycle.
+		while True:
+			root_nodes = mygraph.root_nodes(
+				ignore_priority=DepPrioritySatisfiedRange.ignore_medium_soft)
+			if not root_nodes:
+				break
+			mygraph.difference_update(root_nodes)
+		# Display the USE flags that are enabled on nodes that are part
+		# of dependency cycles in case that helps the user decide to
+		# disable some of them.
+		display_order = []
+		tempgraph = mygraph.copy()
+		while not tempgraph.empty():
+			nodes = tempgraph.leaf_nodes()
+			if not nodes:
+				node = tempgraph.order[0]
+			else:
+				node = nodes[0]
+			display_order.append(node)
+			tempgraph.remove(node)
+		display_order.reverse()
+		self.myopts.pop("--quiet", None)
+		self.myopts.pop("--verbose", None)
+		self.myopts["--tree"] = True
+		portage.writemsg("\n\n", noiselevel=-1)
+		self.display(display_order)
+		prefix = colorize("BAD", " * ")
+		portage.writemsg("\n", noiselevel=-1)
+		portage.writemsg(prefix + "Error: circular dependencies:\n",
+			noiselevel=-1)
+		portage.writemsg("\n", noiselevel=-1)
+		mygraph.debug_print()
+		portage.writemsg("\n", noiselevel=-1)
+		portage.writemsg(prefix + "Note that circular dependencies " + \
+			"can often be avoided by temporarily\n", noiselevel=-1)
+		portage.writemsg(prefix + "disabling USE flags that trigger " + \
+			"optional dependencies.\n", noiselevel=-1)
+
+	def _show_merge_list(self):
+		if self._serialized_tasks_cache is not None and \
+			not (self._displayed_list and \
+			(self._displayed_list == self._serialized_tasks_cache or \
+			self._displayed_list == \
+				list(reversed(self._serialized_tasks_cache)))):
+			display_list = self._serialized_tasks_cache[:]
+			if "--tree" in self.myopts:
+				display_list.reverse()
+			self.display(display_list)
+
+	def _show_unsatisfied_blockers(self, blockers):
+		self._show_merge_list()
+		msg = "Error: The above package list contains " + \
+			"packages which cannot be installed " + \
+			"at the same time on the same system."
+		prefix = colorize("BAD", " * ")
+		from textwrap import wrap
+		portage.writemsg("\n", noiselevel=-1)
+		for line in wrap(msg, 70):
+			portage.writemsg(prefix + line + "\n", noiselevel=-1)
+
+		# Display the conflicting packages along with the packages
+		# that pulled them in. This is helpful for troubleshooting
+		# cases in which blockers don't solve automatically and
+		# the reasons are not apparent from the normal merge list
+		# display.
+
+		conflict_pkgs = {}
+		for blocker in blockers:
+			for pkg in chain(self._blocked_pkgs.child_nodes(blocker), \
+				self._blocker_parents.parent_nodes(blocker)):
+				parent_atoms = self._parent_atoms.get(pkg)
+				if not parent_atoms:
+					atom = self._blocked_world_pkgs.get(pkg)
+					if atom is not None:
+						parent_atoms = set([("@world", atom)])
+				if parent_atoms:
+					conflict_pkgs[pkg] = parent_atoms
+
+		if conflict_pkgs:
+			# Reduce noise by pruning packages that are only
+			# pulled in by other conflict packages.
+			pruned_pkgs = set()
+			for pkg, parent_atoms in conflict_pkgs.iteritems():
+				relevant_parent = False
+				for parent, atom in parent_atoms:
+					if parent not in conflict_pkgs:
+						relevant_parent = True
+						break
+				if not relevant_parent:
+					pruned_pkgs.add(pkg)
+			for pkg in pruned_pkgs:
+				del conflict_pkgs[pkg]
+
+		if conflict_pkgs:
+			msg = []
+			msg.append("\n")
+			indent = "  "
+			# Max number of parents shown, to avoid flooding the display.
+			max_parents = 3
+			for pkg, parent_atoms in conflict_pkgs.iteritems():
+
+				pruned_list = set()
+
+				# Prefer packages that are not directly involved in a conflict.
+				for parent_atom in parent_atoms:
+					if len(pruned_list) >= max_parents:
+						break
+					parent, atom = parent_atom
+					if parent not in conflict_pkgs:
+						pruned_list.add(parent_atom)
+
+				for parent_atom in parent_atoms:
+					if len(pruned_list) >= max_parents:
+						break
+					pruned_list.add(parent_atom)
+
+				omitted_parents = len(parent_atoms) - len(pruned_list)
+				msg.append(indent + "%s pulled in by\n" % pkg)
+
+				for parent_atom in pruned_list:
+					parent, atom = parent_atom
+					msg.append(2*indent)
+					if isinstance(parent,
+						(PackageArg, AtomArg)):
+						# For PackageArg and AtomArg types, it's
+						# redundant to display the atom attribute.
+						msg.append(str(parent))
+					else:
+						# Display the specific atom from SetArg or
+						# Package types.
+						msg.append("%s required by %s" % (atom, parent))
+					msg.append("\n")
+
+				if omitted_parents:
+					msg.append(2*indent)
+					msg.append("(and %d more)\n" % omitted_parents)
+
+				msg.append("\n")
+
+			sys.stderr.write("".join(msg))
+			sys.stderr.flush()
+
+		if "--quiet" not in self.myopts:
+			show_blocker_docs_link()
+
+	def display(self, mylist, favorites=[], verbosity=None):
+
+		# This is used to prevent display_problems() from
+		# redundantly displaying this exact same merge list
+		# again via _show_merge_list().
+		self._displayed_list = mylist
+
+		if verbosity is None:
+			verbosity = ("--quiet" in self.myopts and 1 or \
+				"--verbose" in self.myopts and 3 or 2)
+		favorites_set = InternalPackageSet(favorites)
+		oneshot = "--oneshot" in self.myopts or \
+			"--onlydeps" in self.myopts
+		columns = "--columns" in self.myopts
+		changelogs=[]
+		p=[]
+		blockers = []
+
+		counters = PackageCounters()
+
+		if verbosity == 1 and "--verbose" not in self.myopts:
+			def create_use_string(*args):
+				return ""
+		else:
+			def create_use_string(name, cur_iuse, iuse_forced, cur_use,
+				old_iuse, old_use,
+				is_new, reinst_flags,
+				all_flags=(verbosity == 3 or "--quiet" in self.myopts),
+				alphabetical=("--alphabetical" in self.myopts)):
+				enabled = []
+				if alphabetical:
+					disabled = enabled
+					removed = enabled
+				else:
+					disabled = []
+					removed = []
+				cur_iuse = set(cur_iuse)
+				enabled_flags = cur_iuse.intersection(cur_use)
+				removed_iuse = set(old_iuse).difference(cur_iuse)
+				any_iuse = cur_iuse.union(old_iuse)
+				any_iuse = list(any_iuse)
+				any_iuse.sort()
+				for flag in any_iuse:
+					flag_str = None
+					isEnabled = False
+					reinst_flag = reinst_flags and flag in reinst_flags
+					if flag in enabled_flags:
+						isEnabled = True
+						if is_new or flag in old_use and \
+							(all_flags or reinst_flag):
+							flag_str = red(flag)
+						elif flag not in old_iuse:
+							flag_str = yellow(flag) + "%*"
+						elif flag not in old_use:
+							flag_str = green(flag) + "*"
+					elif flag in removed_iuse:
+						if all_flags or reinst_flag:
+							flag_str = yellow("-" + flag) + "%"
+							if flag in old_use:
+								flag_str += "*"
+							flag_str = "(" + flag_str + ")"
+							removed.append(flag_str)
+						continue
+					else:
+						if is_new or flag in old_iuse and \
+							flag not in old_use and \
+							(all_flags or reinst_flag):
+							flag_str = blue("-" + flag)
+						elif flag not in old_iuse:
+							flag_str = yellow("-" + flag)
+							if flag not in iuse_forced:
+								flag_str += "%"
+						elif flag in old_use:
+							flag_str = green("-" + flag) + "*"
+					if flag_str:
+						if flag in iuse_forced:
+							flag_str = "(" + flag_str + ")"
+						if isEnabled:
+							enabled.append(flag_str)
+						else:
+							disabled.append(flag_str)
+
+				if alphabetical:
+					ret = " ".join(enabled)
+				else:
+					ret = " ".join(enabled + disabled + removed)
+				if ret:
+					ret = '%s="%s" ' % (name, ret)
+				return ret
+
+		repo_display = RepoDisplay(self.roots)
+
+		tree_nodes = []
+		display_list = []
+		mygraph = self.digraph.copy()
+
+		# If there are any Uninstall instances, add the corresponding
+		# blockers to the digraph (useful for --tree display).
+
+		executed_uninstalls = set(node for node in mylist \
+			if isinstance(node, Package) and node.operation == "unmerge")
+
+		for uninstall in self._blocker_uninstalls.leaf_nodes():
+			uninstall_parents = \
+				self._blocker_uninstalls.parent_nodes(uninstall)
+			if not uninstall_parents:
+				continue
+
+			# Remove the corresponding "nomerge" node and substitute
+			# the Uninstall node.
+			inst_pkg = self._pkg_cache[
+				("installed", uninstall.root, uninstall.cpv, "nomerge")]
+			try:
+				mygraph.remove(inst_pkg)
+			except KeyError:
+				pass
+
+			try:
+				inst_pkg_blockers = self._blocker_parents.child_nodes(inst_pkg)
+			except KeyError:
+				inst_pkg_blockers = []
+
+			# Break the Package -> Uninstall edges.
+			mygraph.remove(uninstall)
+
+			# Resolution of a package's blockers
+			# depend on it's own uninstallation.
+			for blocker in inst_pkg_blockers:
+				mygraph.add(uninstall, blocker)
+
+			# Expand Package -> Uninstall edges into
+			# Package -> Blocker -> Uninstall edges.
+			for blocker in uninstall_parents:
+				mygraph.add(uninstall, blocker)
+				for parent in self._blocker_parents.parent_nodes(blocker):
+					if parent != inst_pkg:
+						mygraph.add(blocker, parent)
+
+			# If the uninstall task did not need to be executed because
+			# of an upgrade, display Blocker -> Upgrade edges since the
+			# corresponding Blocker -> Uninstall edges will not be shown.
+			upgrade_node = \
+				self._slot_pkg_map[uninstall.root].get(uninstall.slot_atom)
+			if upgrade_node is not None and \
+				uninstall not in executed_uninstalls:
+				for blocker in uninstall_parents:
+					mygraph.add(upgrade_node, blocker)
+
+		unsatisfied_blockers = []
+		i = 0
+		depth = 0
+		shown_edges = set()
+		for x in mylist:
+			if isinstance(x, Blocker) and not x.satisfied:
+				unsatisfied_blockers.append(x)
+				continue
+			graph_key = x
+			if "--tree" in self.myopts:
+				depth = len(tree_nodes)
+				while depth and graph_key not in \
+					mygraph.child_nodes(tree_nodes[depth-1]):
+						depth -= 1
+				if depth:
+					tree_nodes = tree_nodes[:depth]
+					tree_nodes.append(graph_key)
+					display_list.append((x, depth, True))
+					shown_edges.add((graph_key, tree_nodes[depth-1]))
+				else:
+					traversed_nodes = set() # prevent endless circles
+					traversed_nodes.add(graph_key)
+					def add_parents(current_node, ordered):
+						parent_nodes = None
+						# Do not traverse to parents if this node is an
+						# an argument or a direct member of a set that has
+						# been specified as an argument (system or world).
+						if current_node not in self._set_nodes:
+							parent_nodes = mygraph.parent_nodes(current_node)
+						if parent_nodes:
+							child_nodes = set(mygraph.child_nodes(current_node))
+							selected_parent = None
+							# First, try to avoid a direct cycle.
+							for node in parent_nodes:
+								if not isinstance(node, (Blocker, Package)):
+									continue
+								if node not in traversed_nodes and \
+									node not in child_nodes:
+									edge = (current_node, node)
+									if edge in shown_edges:
+										continue
+									selected_parent = node
+									break
+							if not selected_parent:
+								# A direct cycle is unavoidable.
+								for node in parent_nodes:
+									if not isinstance(node, (Blocker, Package)):
+										continue
+									if node not in traversed_nodes:
+										edge = (current_node, node)
+										if edge in shown_edges:
+											continue
+										selected_parent = node
+										break
+							if selected_parent:
+								shown_edges.add((current_node, selected_parent))
+								traversed_nodes.add(selected_parent)
+								add_parents(selected_parent, False)
+						display_list.append((current_node,
+							len(tree_nodes), ordered))
+						tree_nodes.append(current_node)
+					tree_nodes = []
+					add_parents(graph_key, True)
+			else:
+				display_list.append((x, depth, True))
+		mylist = display_list
+		for x in unsatisfied_blockers:
+			mylist.append((x, 0, True))
+
+		last_merge_depth = 0
+		for i in xrange(len(mylist)-1,-1,-1):
+			graph_key, depth, ordered = mylist[i]
+			if not ordered and depth == 0 and i > 0 \
+				and graph_key == mylist[i-1][0] and \
+				mylist[i-1][1] == 0:
+				# An ordered node got a consecutive duplicate when the tree was
+				# being filled in.
+				del mylist[i]
+				continue
+			if ordered and graph_key[-1] != "nomerge":
+				last_merge_depth = depth
+				continue
+			if depth >= last_merge_depth or \
+				i < len(mylist) - 1 and \
+				depth >= mylist[i+1][1]:
+					del mylist[i]
+
+		from portage import flatten
+		from portage.dep import use_reduce, paren_reduce
+		# files to fetch list - avoids counting a same file twice
+		# in size display (verbose mode)
+		myfetchlist=[]
+
+		# Use this set to detect when all the "repoadd" strings are "[0]"
+		# and disable the entire repo display in this case.
+		repoadd_set = set()
+
+		for mylist_index in xrange(len(mylist)):
+			x, depth, ordered = mylist[mylist_index]
+			pkg_type = x[0]
+			myroot = x[1]
+			pkg_key = x[2]
+			portdb = self.trees[myroot]["porttree"].dbapi
+			bindb  = self.trees[myroot]["bintree"].dbapi
+			vardb = self.trees[myroot]["vartree"].dbapi
+			vartree = self.trees[myroot]["vartree"]
+			pkgsettings = self.pkgsettings[myroot]
+
+			fetch=" "
+			indent = " " * depth
+
+			if isinstance(x, Blocker):
+				if x.satisfied:
+					blocker_style = "PKG_BLOCKER_SATISFIED"
+					addl = "%s  %s  " % (colorize(blocker_style, "b"), fetch)
+				else:
+					blocker_style = "PKG_BLOCKER"
+					addl = "%s  %s  " % (colorize(blocker_style, "B"), fetch)
+				if ordered:
+					counters.blocks += 1
+					if x.satisfied:
+						counters.blocks_satisfied += 1
+				resolved = portage.key_expand(
+					str(x.atom).lstrip("!"), mydb=vardb, settings=pkgsettings)
+				if "--columns" in self.myopts and "--quiet" in self.myopts:
+					addl += " " + colorize(blocker_style, resolved)
+				else:
+					addl = "[%s %s] %s%s" % \
+						(colorize(blocker_style, "blocks"),
+						addl, indent, colorize(blocker_style, resolved))
+				block_parents = self._blocker_parents.parent_nodes(x)
+				block_parents = set([pnode[2] for pnode in block_parents])
+				block_parents = ", ".join(block_parents)
+				if resolved!=x[2]:
+					addl += colorize(blocker_style,
+						" (\"%s\" is blocking %s)") % \
+						(str(x.atom).lstrip("!"), block_parents)
+				else:
+					addl += colorize(blocker_style,
+						" (is blocking %s)") % block_parents
+				if isinstance(x, Blocker) and x.satisfied:
+					if columns:
+						continue
+					p.append(addl)
+				else:
+					blockers.append(addl)
+			else:
+				pkg_status = x[3]
+				pkg_merge = ordered and pkg_status == "merge"
+				if not pkg_merge and pkg_status == "merge":
+					pkg_status = "nomerge"
+				built = pkg_type != "ebuild"
+				installed = pkg_type == "installed"
+				pkg = x
+				metadata = pkg.metadata
+				ebuild_path = None
+				repo_name = metadata["repository"]
+				if pkg_type == "ebuild":
+					ebuild_path = portdb.findname(pkg_key)
+					if not ebuild_path: # shouldn't happen
+						raise portage.exception.PackageNotFound(pkg_key)
+					repo_path_real = os.path.dirname(os.path.dirname(
+						os.path.dirname(ebuild_path)))
+				else:
+					repo_path_real = portdb.getRepositoryPath(repo_name)
+				pkg_use = list(pkg.use.enabled)
+				try:
+					restrict = flatten(use_reduce(paren_reduce(
+						pkg.metadata["RESTRICT"]), uselist=pkg_use))
+				except portage.exception.InvalidDependString, e:
+					if not pkg.installed:
+						show_invalid_depstring_notice(x,
+							pkg.metadata["RESTRICT"], str(e))
+						del e
+						return 1
+					restrict = []
+				if "ebuild" == pkg_type and x[3] != "nomerge" and \
+					"fetch" in restrict:
+					fetch = red("F")
+					if ordered:
+						counters.restrict_fetch += 1
+					if portdb.fetch_check(pkg_key, pkg_use):
+						fetch = green("f")
+						if ordered:
+							counters.restrict_fetch_satisfied += 1
+
+				#we need to use "--emptrytree" testing here rather than "empty" param testing because "empty"
+				#param is used for -u, where you still *do* want to see when something is being upgraded.
+				myoldbest = []
+				myinslotlist = None
+				installed_versions = vardb.match(portage.cpv_getkey(pkg_key))
+				if vardb.cpv_exists(pkg_key):
+					addl="  "+yellow("R")+fetch+"  "
+					if ordered:
+						if pkg_merge:
+							counters.reinst += 1
+						elif pkg_status == "uninstall":
+							counters.uninst += 1
+				# filter out old-style virtual matches
+				elif installed_versions and \
+					portage.cpv_getkey(installed_versions[0]) == \
+					portage.cpv_getkey(pkg_key):
+					myinslotlist = vardb.match(pkg.slot_atom)
+					# If this is the first install of a new-style virtual, we
+					# need to filter out old-style virtual matches.
+					if myinslotlist and \
+						portage.cpv_getkey(myinslotlist[0]) != \
+						portage.cpv_getkey(pkg_key):
+						myinslotlist = None
+					if myinslotlist:
+						myoldbest = myinslotlist[:]
+						addl = "   " + fetch
+						if not portage.dep.cpvequal(pkg_key,
+							portage.best([pkg_key] + myoldbest)):
+							# Downgrade in slot
+							addl += turquoise("U")+blue("D")
+							if ordered:
+								counters.downgrades += 1
+						else:
+							# Update in slot
+							addl += turquoise("U") + " "
+							if ordered:
+								counters.upgrades += 1
+					else:
+						# New slot, mark it new.
+						addl = " " + green("NS") + fetch + "  "
+						myoldbest = vardb.match(portage.cpv_getkey(pkg_key))
+						if ordered:
+							counters.newslot += 1
+
+					if "--changelog" in self.myopts:
+						inst_matches = vardb.match(pkg.slot_atom)
+						if inst_matches:
+							changelogs.extend(self.calc_changelog(
+								portdb.findname(pkg_key),
+								inst_matches[0], pkg_key))
+				else:
+					addl = " " + green("N") + " " + fetch + "  "
+					if ordered:
+						counters.new += 1
+
+				verboseadd = ""
+				repoadd = None
+
+				if True:
+					# USE flag display
+					forced_flags = set()
+					pkgsettings.setcpv(pkg) # for package.use.{mask,force}
+					forced_flags.update(pkgsettings.useforce)
+					forced_flags.update(pkgsettings.usemask)
+
+					cur_use = [flag for flag in pkg.use.enabled \
+						if flag in pkg.iuse.all]
+					cur_iuse = sorted(pkg.iuse.all)
+
+					if myoldbest and myinslotlist:
+						previous_cpv = myoldbest[0]
+					else:
+						previous_cpv = pkg.cpv
+					if vardb.cpv_exists(previous_cpv):
+						old_iuse, old_use = vardb.aux_get(
+								previous_cpv, ["IUSE", "USE"])
+						old_iuse = list(set(
+							filter_iuse_defaults(old_iuse.split())))
+						old_iuse.sort()
+						old_use = old_use.split()
+						is_new = False
+					else:
+						old_iuse = []
+						old_use = []
+						is_new = True
+
+					old_use = [flag for flag in old_use if flag in old_iuse]
+
+					use_expand = pkgsettings["USE_EXPAND"].lower().split()
+					use_expand.sort()
+					use_expand.reverse()
+					use_expand_hidden = \
+						pkgsettings["USE_EXPAND_HIDDEN"].lower().split()
+
+					def map_to_use_expand(myvals, forcedFlags=False,
+						removeHidden=True):
+						ret = {}
+						forced = {}
+						for exp in use_expand:
+							ret[exp] = []
+							forced[exp] = set()
+							for val in myvals[:]:
+								if val.startswith(exp.lower()+"_"):
+									if val in forced_flags:
+										forced[exp].add(val[len(exp)+1:])
+									ret[exp].append(val[len(exp)+1:])
+									myvals.remove(val)
+						ret["USE"] = myvals
+						forced["USE"] = [val for val in myvals \
+							if val in forced_flags]
+						if removeHidden:
+							for exp in use_expand_hidden:
+								ret.pop(exp, None)
+						if forcedFlags:
+							return ret, forced
+						return ret
+
+					# Prevent USE_EXPAND_HIDDEN flags from being hidden if they
+					# are the only thing that triggered reinstallation.
+					reinst_flags_map = {}
+					reinstall_for_flags = self._reinstall_nodes.get(pkg)
+					reinst_expand_map = None
+					if reinstall_for_flags:
+						reinst_flags_map = map_to_use_expand(
+							list(reinstall_for_flags), removeHidden=False)
+						for k in list(reinst_flags_map):
+							if not reinst_flags_map[k]:
+								del reinst_flags_map[k]
+						if not reinst_flags_map.get("USE"):
+							reinst_expand_map = reinst_flags_map.copy()
+							reinst_expand_map.pop("USE", None)
+					if reinst_expand_map and \
+						not set(reinst_expand_map).difference(
+						use_expand_hidden):
+						use_expand_hidden = \
+							set(use_expand_hidden).difference(
+							reinst_expand_map)
+
+					cur_iuse_map, iuse_forced = \
+						map_to_use_expand(cur_iuse, forcedFlags=True)
+					cur_use_map = map_to_use_expand(cur_use)
+					old_iuse_map = map_to_use_expand(old_iuse)
+					old_use_map = map_to_use_expand(old_use)
+
+					use_expand.sort()
+					use_expand.insert(0, "USE")
+					
+					for key in use_expand:
+						if key in use_expand_hidden:
+							continue
+						verboseadd += create_use_string(key.upper(),
+							cur_iuse_map[key], iuse_forced[key],
+							cur_use_map[key], old_iuse_map[key],
+							old_use_map[key], is_new,
+							reinst_flags_map.get(key))
+
+				if verbosity == 3:
+					# size verbose
+					mysize=0
+					if pkg_type == "ebuild" and pkg_merge:
+						try:
+							myfilesdict = portdb.getfetchsizes(pkg_key,
+								useflags=pkg_use, debug=self.edebug)
+						except portage.exception.InvalidDependString, e:
+							src_uri = portdb.aux_get(pkg_key, ["SRC_URI"])[0]
+							show_invalid_depstring_notice(x, src_uri, str(e))
+							del e
+							return 1
+						if myfilesdict is None:
+							myfilesdict="[empty/missing/bad digest]"
+						else:
+							for myfetchfile in myfilesdict:
+								if myfetchfile not in myfetchlist:
+									mysize+=myfilesdict[myfetchfile]
+									myfetchlist.append(myfetchfile)
+							if ordered:
+								counters.totalsize += mysize
+						verboseadd += format_size(mysize)
+
+					# overlay verbose
+					# assign index for a previous version in the same slot
+					has_previous = False
+					repo_name_prev = None
+					slot_atom = "%s:%s" % (portage.dep_getkey(pkg_key),
+						metadata["SLOT"])
+					slot_matches = vardb.match(slot_atom)
+					if slot_matches:
+						has_previous = True
+						repo_name_prev = vardb.aux_get(slot_matches[0],
+							["repository"])[0]
+
+					# now use the data to generate output
+					if pkg.installed or not has_previous:
+						repoadd = repo_display.repoStr(repo_path_real)
+					else:
+						repo_path_prev = None
+						if repo_name_prev:
+							repo_path_prev = portdb.getRepositoryPath(
+								repo_name_prev)
+						if repo_path_prev == repo_path_real:
+							repoadd = repo_display.repoStr(repo_path_real)
+						else:
+							repoadd = "%s=>%s" % (
+								repo_display.repoStr(repo_path_prev),
+								repo_display.repoStr(repo_path_real))
+					if repoadd:
+						repoadd_set.add(repoadd)
+
+				xs = [portage.cpv_getkey(pkg_key)] + \
+					list(portage.catpkgsplit(pkg_key)[2:])
+				if xs[2] == "r0":
+					xs[2] = ""
+				else:
+					xs[2] = "-" + xs[2]
+
+				mywidth = 130
+				if "COLUMNWIDTH" in self.settings:
+					try:
+						mywidth = int(self.settings["COLUMNWIDTH"])
+					except ValueError, e:
+						portage.writemsg("!!! %s\n" % str(e), noiselevel=-1)
+						portage.writemsg(
+							"!!! Unable to parse COLUMNWIDTH='%s'\n" % \
+							self.settings["COLUMNWIDTH"], noiselevel=-1)
+						del e
+				oldlp = mywidth - 30
+				newlp = oldlp - 30
+
+				# Convert myoldbest from a list to a string.
+				if not myoldbest:
+					myoldbest = ""
+				else:
+					for pos, key in enumerate(myoldbest):
+						key = portage.catpkgsplit(key)[2] + \
+							"-" + portage.catpkgsplit(key)[3]
+						if key[-3:] == "-r0":
+							key = key[:-3]
+						myoldbest[pos] = key
+					myoldbest = blue("["+", ".join(myoldbest)+"]")
+
+				pkg_cp = xs[0]
+				root_config = self.roots[myroot]
+				system_set = root_config.sets["system"]
+				world_set  = root_config.sets["world"]
+
+				pkg_system = False
+				pkg_world = False
+				try:
+					pkg_system = system_set.findAtomForPackage(pkg)
+					pkg_world  = world_set.findAtomForPackage(pkg)
+					if not (oneshot or pkg_world) and \
+						myroot == self.target_root and \
+						favorites_set.findAtomForPackage(pkg):
+						# Maybe it will be added to world now.
+						if create_world_atom(pkg, favorites_set, root_config):
+							pkg_world = True
+				except portage.exception.InvalidDependString:
+					# This is reported elsewhere if relevant.
+					pass
+
+				def pkgprint(pkg_str):
+					if pkg_merge:
+						if pkg_system:
+							return colorize("PKG_MERGE_SYSTEM", pkg_str)
+						elif pkg_world:
+							return colorize("PKG_MERGE_WORLD", pkg_str)
+						else:
+							return colorize("PKG_MERGE", pkg_str)
+					elif pkg_status == "uninstall":
+						return colorize("PKG_UNINSTALL", pkg_str)
+					else:
+						if pkg_system:
+							return colorize("PKG_NOMERGE_SYSTEM", pkg_str)
+						elif pkg_world:
+							return colorize("PKG_NOMERGE_WORLD", pkg_str)
+						else:
+							return colorize("PKG_NOMERGE", pkg_str)
+
+				try:
+					properties = flatten(use_reduce(paren_reduce(
+						pkg.metadata["PROPERTIES"]), uselist=pkg.use.enabled))
+				except portage.exception.InvalidDependString, e:
+					if not pkg.installed:
+						show_invalid_depstring_notice(pkg,
+							pkg.metadata["PROPERTIES"], str(e))
+						del e
+						return 1
+					properties = []
+				interactive = "interactive" in properties
+				if interactive and pkg.operation == "merge":
+					addl = colorize("WARN", "I") + addl[1:]
+					if ordered:
+						counters.interactive += 1
+
+				if x[1]!="/":
+					if myoldbest:
+						myoldbest +=" "
+					if "--columns" in self.myopts:
+						if "--quiet" in self.myopts:
+							myprint=addl+" "+indent+pkgprint(pkg_cp)
+							myprint=myprint+darkblue(" "+xs[1]+xs[2])+" "
+							myprint=myprint+myoldbest
+							myprint=myprint+darkgreen("to "+x[1])
+							verboseadd = None
+						else:
+							if not pkg_merge:
+								myprint = "[%s] %s%s" % \
+									(pkgprint(pkg_status.ljust(13)),
+									indent, pkgprint(pkg.cp))
+							else:
+								myprint = "[%s %s] %s%s" % \
+									(pkgprint(pkg.type_name), addl,
+									indent, pkgprint(pkg.cp))
+							if (newlp-nc_len(myprint)) > 0:
+								myprint=myprint+(" "*(newlp-nc_len(myprint)))
+							myprint=myprint+"["+darkblue(xs[1]+xs[2])+"] "
+							if (oldlp-nc_len(myprint)) > 0:
+								myprint=myprint+" "*(oldlp-nc_len(myprint))
+							myprint=myprint+myoldbest
+							myprint += darkgreen("to " + pkg.root)
+					else:
+						if not pkg_merge:
+							myprint = "[%s] " % pkgprint(pkg_status.ljust(13))
+						else:
+							myprint = "[%s %s] " % (pkgprint(pkg_type), addl)
+						myprint += indent + pkgprint(pkg_key) + " " + \
+							myoldbest + darkgreen("to " + myroot)
+				else:
+					if "--columns" in self.myopts:
+						if "--quiet" in self.myopts:
+							myprint=addl+" "+indent+pkgprint(pkg_cp)
+							myprint=myprint+" "+green(xs[1]+xs[2])+" "
+							myprint=myprint+myoldbest
+							verboseadd = None
+						else:
+							if not pkg_merge:
+								myprint = "[%s] %s%s" % \
+									(pkgprint(pkg_status.ljust(13)),
+									indent, pkgprint(pkg.cp))
+							else:
+								myprint = "[%s %s] %s%s" % \
+									(pkgprint(pkg.type_name), addl,
+									indent, pkgprint(pkg.cp))
+							if (newlp-nc_len(myprint)) > 0:
+								myprint=myprint+(" "*(newlp-nc_len(myprint)))
+							myprint=myprint+green(" ["+xs[1]+xs[2]+"] ")
+							if (oldlp-nc_len(myprint)) > 0:
+								myprint=myprint+(" "*(oldlp-nc_len(myprint)))
+							myprint += myoldbest
+					else:
+						if not pkg_merge:
+							myprint = "[%s] %s%s %s" % \
+								(pkgprint(pkg_status.ljust(13)),
+								indent, pkgprint(pkg.cpv),
+								myoldbest)
+						else:
+							myprint = "[%s %s] %s%s %s" % \
+								(pkgprint(pkg_type), addl, indent,
+								pkgprint(pkg.cpv), myoldbest)
+
+				if columns and pkg.operation == "uninstall":
+					continue
+				p.append((myprint, verboseadd, repoadd))
+
+				if "--tree" not in self.myopts and \
+					"--quiet" not in self.myopts and \
+					not self._opts_no_restart.intersection(self.myopts) and \
+					pkg.root == self._running_root.root and \
+					portage.match_from_list(
+					portage.const.PORTAGE_PACKAGE_ATOM, [pkg]) and \
+					not vardb.cpv_exists(pkg.cpv) and \
+					"--quiet" not in self.myopts:
+						if mylist_index < len(mylist) - 1:
+							p.append(colorize("WARN", "*** Portage will stop merging at this point and reload itself,"))
+							p.append(colorize("WARN", "    then resume the merge."))
+
+		out = sys.stdout
+		show_repos = repoadd_set and repoadd_set != set(["0"])
+
+		for x in p:
+			if isinstance(x, basestring):
+				out.write("%s\n" % (x,))
+				continue
+
+			myprint, verboseadd, repoadd = x
+
+			if verboseadd:
+				myprint += " " + verboseadd
+
+			if show_repos and repoadd:
+				myprint += " " + teal("[%s]" % repoadd)
+
+			out.write("%s\n" % (myprint,))
+
+		for x in blockers:
+			print x
+
+		if verbosity == 3:
+			print
+			print counters
+			if show_repos:
+				sys.stdout.write(str(repo_display))
+
+		if "--changelog" in self.myopts:
+			print
+			for revision,text in changelogs:
+				print bold('*'+revision)
+				sys.stdout.write(text)
+
+		sys.stdout.flush()
+		return os.EX_OK
+
+	def display_problems(self):
+		"""
+		Display problems with the dependency graph such as slot collisions.
+		This is called internally by display() to show the problems _after_
+		the merge list where it is most likely to be seen, but if display()
+		is not going to be called then this method should be called explicitly
+		to ensure that the user is notified of problems with the graph.
+
+		All output goes to stderr, except for unsatisfied dependencies which
+		go to stdout for parsing by programs such as autounmask.
+		"""
+
+		# Note that show_masked_packages() sends it's output to
+		# stdout, and some programs such as autounmask parse the
+		# output in cases when emerge bails out. However, when
+		# show_masked_packages() is called for installed packages
+		# here, the message is a warning that is more appropriate
+		# to send to stderr, so temporarily redirect stdout to
+		# stderr. TODO: Fix output code so there's a cleaner way
+		# to redirect everything to stderr.
+		sys.stdout.flush()
+		sys.stderr.flush()
+		stdout = sys.stdout
+		try:
+			sys.stdout = sys.stderr
+			self._display_problems()
+		finally:
+			sys.stdout = stdout
+			sys.stdout.flush()
+			sys.stderr.flush()
+
+		# This goes to stdout for parsing by programs like autounmask.
+		for pargs, kwargs in self._unsatisfied_deps_for_display:
+			self._show_unsatisfied_dep(*pargs, **kwargs)
+
+	def _display_problems(self):
+		if self._circular_deps_for_display is not None:
+			self._show_circular_deps(
+				self._circular_deps_for_display)
+
+		# The user is only notified of a slot conflict if
+		# there are no unresolvable blocker conflicts.
+		if self._unsatisfied_blockers_for_display is not None:
+			self._show_unsatisfied_blockers(
+				self._unsatisfied_blockers_for_display)
+		else:
+			self._show_slot_collision_notice()
+
+		# TODO: Add generic support for "set problem" handlers so that
+		# the below warnings aren't special cases for world only.
+
+		if self._missing_args:
+			world_problems = False
+			if "world" in self._sets:
+				# Filter out indirect members of world (from nested sets)
+				# since only direct members of world are desired here.
+				world_set = self.roots[self.target_root].sets["world"]
+				for arg, atom in self._missing_args:
+					if arg.name == "world" and atom in world_set:
+						world_problems = True
+						break
+
+			if world_problems:
+				sys.stderr.write("\n!!! Problems have been " + \
+					"detected with your world file\n")
+				sys.stderr.write("!!! Please run " + \
+					green("emaint --check world")+"\n\n")
+
+		if self._missing_args:
+			sys.stderr.write("\n" + colorize("BAD", "!!!") + \
+				" Ebuilds for the following packages are either all\n")
+			sys.stderr.write(colorize("BAD", "!!!") + \
+				" masked or don't exist:\n")
+			sys.stderr.write(" ".join(str(atom) for arg, atom in \
+				self._missing_args) + "\n")
+
+		if self._pprovided_args:
+			arg_refs = {}
+			for arg, atom in self._pprovided_args:
+				if isinstance(arg, SetArg):
+					parent = arg.name
+					arg_atom = (atom, atom)
+				else:
+					parent = "args"
+					arg_atom = (arg.arg, atom)
+				refs = arg_refs.setdefault(arg_atom, [])
+				if parent not in refs:
+					refs.append(parent)
+			msg = []
+			msg.append(bad("\nWARNING: "))
+			if len(self._pprovided_args) > 1:
+				msg.append("Requested packages will not be " + \
+					"merged because they are listed in\n")
+			else:
+				msg.append("A requested package will not be " + \
+					"merged because it is listed in\n")
+			msg.append("package.provided:\n\n")
+			problems_sets = set()
+			for (arg, atom), refs in arg_refs.iteritems():
+				ref_string = ""
+				if refs:
+					problems_sets.update(refs)
+					refs.sort()
+					ref_string = ", ".join(["'%s'" % name for name in refs])
+					ref_string = " pulled in by " + ref_string
+				msg.append("  %s%s\n" % (colorize("INFORM", str(arg)), ref_string))
+			msg.append("\n")
+			if "world" in problems_sets:
+				msg.append("This problem can be solved in one of the following ways:\n\n")
+				msg.append("  A) Use emaint to clean offending packages from world (if not installed).\n")
+				msg.append("  B) Uninstall offending packages (cleans them from world).\n")
+				msg.append("  C) Remove offending entries from package.provided.\n\n")
+				msg.append("The best course of action depends on the reason that an offending\n")
+				msg.append("package.provided entry exists.\n\n")
+			sys.stderr.write("".join(msg))
+
+		masked_packages = []
+		for pkg in self._masked_installed:
+			root_config = pkg.root_config
+			pkgsettings = self.pkgsettings[pkg.root]
+			mreasons = get_masking_status(pkg, pkgsettings, root_config)
+			masked_packages.append((root_config, pkgsettings,
+				pkg.cpv, pkg.metadata, mreasons))
+		if masked_packages:
+			sys.stderr.write("\n" + colorize("BAD", "!!!") + \
+				" The following installed packages are masked:\n")
+			show_masked_packages(masked_packages)
+			show_mask_docs()
+			print
+
+	def calc_changelog(self,ebuildpath,current,next):
+		if ebuildpath == None or not os.path.exists(ebuildpath):
+			return []
+		current = '-'.join(portage.catpkgsplit(current)[1:])
+		if current.endswith('-r0'):
+			current = current[:-3]
+		next = '-'.join(portage.catpkgsplit(next)[1:])
+		if next.endswith('-r0'):
+			next = next[:-3]
+		changelogpath = os.path.join(os.path.split(ebuildpath)[0],'ChangeLog')
+		try:
+			changelog = open(changelogpath).read()
+		except SystemExit, e:
+			raise # Needed else can't exit
+		except:
+			return []
+		divisions = self.find_changelog_tags(changelog)
+		#print 'XX from',current,'to',next
+		#for div,text in divisions: print 'XX',div
+		# skip entries for all revisions above the one we are about to emerge
+		for i in range(len(divisions)):
+			if divisions[i][0]==next:
+				divisions = divisions[i:]
+				break
+		# find out how many entries we are going to display
+		for i in range(len(divisions)):
+			if divisions[i][0]==current:
+				divisions = divisions[:i]
+				break
+		else:
+		    # couldnt find the current revision in the list. display nothing
+			return []
+		return divisions
+
+	def find_changelog_tags(self,changelog):
+		divs = []
+		release = None
+		while 1:
+			match = re.search(r'^\*\ ?([-a-zA-Z0-9_.+]*)(?:\ .*)?\n',changelog,re.M)
+			if match is None:
+				if release is not None:
+					divs.append((release,changelog))
+				return divs
+			if release is not None:
+				divs.append((release,changelog[:match.start()]))
+			changelog = changelog[match.end():]
+			release = match.group(1)
+			if release.endswith('.ebuild'):
+				release = release[:-7]
+			if release.endswith('-r0'):
+				release = release[:-3]
+
+	def saveNomergeFavorites(self):
+		"""Find atoms in favorites that are not in the mergelist and add them
+		to the world file if necessary."""
+		for x in ("--buildpkgonly", "--fetchonly", "--fetch-all-uri",
+			"--oneshot", "--onlydeps", "--pretend"):
+			if x in self.myopts:
+				return
+		root_config = self.roots[self.target_root]
+		world_set = root_config.sets["world"]
+
+		world_locked = False
+		if hasattr(world_set, "lock"):
+			world_set.lock()
+			world_locked = True
+
+		if hasattr(world_set, "load"):
+			world_set.load() # maybe it's changed on disk
+
+		args_set = self._sets["args"]
+		portdb = self.trees[self.target_root]["porttree"].dbapi
+		added_favorites = set()
+		for x in self._set_nodes:
+			pkg_type, root, pkg_key, pkg_status = x
+			if pkg_status != "nomerge":
+				continue
+
+			try:
+				myfavkey = create_world_atom(x, args_set, root_config)
+				if myfavkey:
+					if myfavkey in added_favorites:
+						continue
+					added_favorites.add(myfavkey)
+			except portage.exception.InvalidDependString, e:
+				writemsg("\n\n!!! '%s' has invalid PROVIDE: %s\n" % \
+					(pkg_key, str(e)), noiselevel=-1)
+				writemsg("!!! see '%s'\n\n" % os.path.join(
+					root, portage.VDB_PATH, pkg_key, "PROVIDE"), noiselevel=-1)
+				del e
+		all_added = []
+		for k in self._sets:
+			if k in ("args", "world") or not root_config.sets[k].world_candidate:
+				continue
+			s = SETPREFIX + k
+			if s in world_set:
+				continue
+			all_added.append(SETPREFIX + k)
+		all_added.extend(added_favorites)
+		all_added.sort()
+		for a in all_added:
+			print ">>> Recording %s in \"world\" favorites file..." % \
+				colorize("INFORM", str(a))
+		if all_added:
+			world_set.update(all_added)
+
+		if world_locked:
+			world_set.unlock()
+
+	def loadResumeCommand(self, resume_data, skip_masked=True,
+		skip_missing=True):
+		"""
+		Add a resume command to the graph and validate it in the process.  This
+		will raise a PackageNotFound exception if a package is not available.
+		"""
+
+		if not isinstance(resume_data, dict):
+			return False
+
+		mergelist = resume_data.get("mergelist")
+		if not isinstance(mergelist, list):
+			mergelist = []
+
+		fakedb = self.mydbapi
+		trees = self.trees
+		serialized_tasks = []
+		masked_tasks = []
+		for x in mergelist:
+			if not (isinstance(x, list) and len(x) == 4):
+				continue
+			pkg_type, myroot, pkg_key, action = x
+			if pkg_type not in self.pkg_tree_map:
+				continue
+			if action != "merge":
+				continue
+			tree_type = self.pkg_tree_map[pkg_type]
+			mydb = trees[myroot][tree_type].dbapi
+			db_keys = list(self._trees_orig[myroot][
+				tree_type].dbapi._aux_cache_keys)
+			try:
+				metadata = izip(db_keys, mydb.aux_get(pkg_key, db_keys))
+			except KeyError:
+				# It does no exist or it is corrupt.
+				if action == "uninstall":
+					continue
+				if skip_missing:
+					# TODO: log these somewhere
+					continue
+				raise portage.exception.PackageNotFound(pkg_key)
+			installed = action == "uninstall"
+			built = pkg_type != "ebuild"
+			root_config = self.roots[myroot]
+			pkg = Package(built=built, cpv=pkg_key,
+				installed=installed, metadata=metadata,
+				operation=action, root_config=root_config,
+				type_name=pkg_type)
+			if pkg_type == "ebuild":
+				pkgsettings = self.pkgsettings[myroot]
+				pkgsettings.setcpv(pkg)
+				pkg.metadata["USE"] = pkgsettings["PORTAGE_USE"]
+				pkg.metadata['CHOST'] = pkgsettings.get('CHOST', '')
+			self._pkg_cache[pkg] = pkg
+
+			root_config = self.roots[pkg.root]
+			if "merge" == pkg.operation and \
+				not visible(root_config.settings, pkg):
+				if skip_masked:
+					masked_tasks.append(Dependency(root=pkg.root, parent=pkg))
+				else:
+					self._unsatisfied_deps_for_display.append(
+						((pkg.root, "="+pkg.cpv), {"myparent":None}))
+
+			fakedb[myroot].cpv_inject(pkg)
+			serialized_tasks.append(pkg)
+			self.spinner.update()
+
+		if self._unsatisfied_deps_for_display:
+			return False
+
+		if not serialized_tasks or "--nodeps" in self.myopts:
+			self._serialized_tasks_cache = serialized_tasks
+			self._scheduler_graph = self.digraph
+		else:
+			self._select_package = self._select_pkg_from_graph
+			self.myparams.add("selective")
+			# Always traverse deep dependencies in order to account for
+			# potentially unsatisfied dependencies of installed packages.
+			# This is necessary for correct --keep-going or --resume operation
+			# in case a package from a group of circularly dependent packages
+			# fails. In this case, a package which has recently been installed
+			# may have an unsatisfied circular dependency (pulled in by
+			# PDEPEND, for example). So, even though a package is already
+			# installed, it may not have all of it's dependencies satisfied, so
+			# it may not be usable. If such a package is in the subgraph of
+			# deep depenedencies of a scheduled build, that build needs to
+			# be cancelled. In order for this type of situation to be
+			# recognized, deep traversal of dependencies is required.
+			self.myparams.add("deep")
+
+			favorites = resume_data.get("favorites")
+			args_set = self._sets["args"]
+			if isinstance(favorites, list):
+				args = self._load_favorites(favorites)
+			else:
+				args = []
+
+			for task in serialized_tasks:
+				if isinstance(task, Package) and \
+					task.operation == "merge":
+					if not self._add_pkg(task, None):
+						return False
+
+			# Packages for argument atoms need to be explicitly
+			# added via _add_pkg() so that they are included in the
+			# digraph (needed at least for --tree display).
+			for arg in args:
+				for atom in arg.set:
+					pkg, existing_node = self._select_package(
+						arg.root_config.root, atom)
+					if existing_node is None and \
+						pkg is not None:
+						if not self._add_pkg(pkg, Dependency(atom=atom,
+							root=pkg.root, parent=arg)):
+							return False
+
+			# Allow unsatisfied deps here to avoid showing a masking
+			# message for an unsatisfied dep that isn't necessarily
+			# masked.
+			if not self._create_graph(allow_unsatisfied=True):
+				return False
+
+			unsatisfied_deps = []
+			for dep in self._unsatisfied_deps:
+				if not isinstance(dep.parent, Package):
+					continue
+				if dep.parent.operation == "merge":
+					unsatisfied_deps.append(dep)
+					continue
+
+				# For unsatisfied deps of installed packages, only account for
+				# them if they are in the subgraph of dependencies of a package
+				# which is scheduled to be installed.
+				unsatisfied_install = False
+				traversed = set()
+				dep_stack = self.digraph.parent_nodes(dep.parent)
+				while dep_stack:
+					node = dep_stack.pop()
+					if not isinstance(node, Package):
+						continue
+					if node.operation == "merge":
+						unsatisfied_install = True
+						break
+					if node in traversed:
+						continue
+					traversed.add(node)
+					dep_stack.extend(self.digraph.parent_nodes(node))
+
+				if unsatisfied_install:
+					unsatisfied_deps.append(dep)
+
+			if masked_tasks or unsatisfied_deps:
+				# This probably means that a required package
+				# was dropped via --skipfirst. It makes the
+				# resume list invalid, so convert it to a
+				# UnsatisfiedResumeDep exception.
+				raise self.UnsatisfiedResumeDep(self,
+					masked_tasks + unsatisfied_deps)
+			self._serialized_tasks_cache = None
+			try:
+				self.altlist()
+			except self._unknown_internal_error:
+				return False
+
+		return True
+
+	def _load_favorites(self, favorites):
+		"""
+		Use a list of favorites to resume state from a
+		previous select_files() call. This creates similar
+		DependencyArg instances to those that would have
+		been created by the original select_files() call.
+		This allows Package instances to be matched with
+		DependencyArg instances during graph creation.
+		"""
+		root_config = self.roots[self.target_root]
+		getSetAtoms = root_config.setconfig.getSetAtoms
+		sets = root_config.sets
+		args = []
+		for x in favorites:
+			if not isinstance(x, basestring):
+				continue
+			if x in ("system", "world"):
+				x = SETPREFIX + x
+			if x.startswith(SETPREFIX):
+				s = x[len(SETPREFIX):]
+				if s not in sets:
+					continue
+				if s in self._sets:
+					continue
+				# Recursively expand sets so that containment tests in
+				# self._get_parent_sets() properly match atoms in nested
+				# sets (like if world contains system).
+				expanded_set = InternalPackageSet(
+					initial_atoms=getSetAtoms(s))
+				self._sets[s] = expanded_set
+				args.append(SetArg(arg=x, set=expanded_set,
+					root_config=root_config))
+			else:
+				if not portage.isvalidatom(x):
+					continue
+				args.append(AtomArg(arg=x, atom=x,
+					root_config=root_config))
+
+		self._set_args(args)
+		return args
+
+	class UnsatisfiedResumeDep(portage.exception.PortageException):
+		"""
+		A dependency of a resume list is not installed. This
+		can occur when a required package is dropped from the
+		merge list via --skipfirst.
+		"""
+		def __init__(self, depgraph, value):
+			portage.exception.PortageException.__init__(self, value)
+			self.depgraph = depgraph
+
+	class _internal_exception(portage.exception.PortageException):
+		def __init__(self, value=""):
+			portage.exception.PortageException.__init__(self, value)
+
+	class _unknown_internal_error(_internal_exception):
+		"""
+		Used by the depgraph internally to terminate graph creation.
+		The specific reason for the failure should have been dumped
+		to stderr, unfortunately, the exact reason for the failure
+		may not be known.
+		"""
+
+	class _serialize_tasks_retry(_internal_exception):
+		"""
+		This is raised by the _serialize_tasks() method when it needs to
+		be called again for some reason. The only case that it's currently
+		used for is when neglected dependencies need to be added to the
+		graph in order to avoid making a potentially unsafe decision.
+		"""
+
+	class _dep_check_composite_db(portage.dbapi):
+		"""
+		A dbapi-like interface that is optimized for use in dep_check() calls.
+		This is built on top of the existing depgraph package selection logic.
+		Some packages that have been added to the graph may be masked from this
+		view in order to influence the atom preference selection that occurs
+		via dep_check().
+		"""
+		def __init__(self, depgraph, root):
+			portage.dbapi.__init__(self)
+			self._depgraph = depgraph
+			self._root = root
+			self._match_cache = {}
+			self._cpv_pkg_map = {}
+
+		def _clear_cache(self):
+			self._match_cache.clear()
+			self._cpv_pkg_map.clear()
+
+		def match(self, atom):
+			ret = self._match_cache.get(atom)
+			if ret is not None:
+				return ret[:]
+			orig_atom = atom
+			if "/" not in atom:
+				atom = self._dep_expand(atom)
+			pkg, existing = self._depgraph._select_package(self._root, atom)
+			if not pkg:
+				ret = []
+			else:
+				# Return the highest available from select_package() as well as
+				# any matching slots in the graph db.
+				slots = set()
+				slots.add(pkg.metadata["SLOT"])
+				atom_cp = portage.dep_getkey(atom)
+				if pkg.cp.startswith("virtual/"):
+					# For new-style virtual lookahead that occurs inside
+					# dep_check(), examine all slots. This is needed
+					# so that newer slots will not unnecessarily be pulled in
+					# when a satisfying lower slot is already installed. For
+					# example, if virtual/jdk-1.4 is satisfied via kaffe then
+					# there's no need to pull in a newer slot to satisfy a
+					# virtual/jdk dependency.
+					for db, pkg_type, built, installed, db_keys in \
+						self._depgraph._filtered_trees[self._root]["dbs"]:
+						for cpv in db.match(atom):
+							if portage.cpv_getkey(cpv) != pkg.cp:
+								continue
+							slots.add(db.aux_get(cpv, ["SLOT"])[0])
+				ret = []
+				if self._visible(pkg):
+					self._cpv_pkg_map[pkg.cpv] = pkg
+					ret.append(pkg.cpv)
+				slots.remove(pkg.metadata["SLOT"])
+				while slots:
+					slot_atom = "%s:%s" % (atom_cp, slots.pop())
+					pkg, existing = self._depgraph._select_package(
+						self._root, slot_atom)
+					if not pkg:
+						continue
+					if not self._visible(pkg):
+						continue
+					self._cpv_pkg_map[pkg.cpv] = pkg
+					ret.append(pkg.cpv)
+				if ret:
+					self._cpv_sort_ascending(ret)
+			self._match_cache[orig_atom] = ret
+			return ret[:]
+
+		def _visible(self, pkg):
+			if pkg.installed and "selective" not in self._depgraph.myparams:
+				try:
+					arg = self._depgraph._iter_atoms_for_pkg(pkg).next()
+				except (StopIteration, portage.exception.InvalidDependString):
+					arg = None
+				if arg:
+					return False
+			if pkg.installed:
+				try:
+					if not visible(
+						self._depgraph.pkgsettings[pkg.root], pkg):
+						return False
+				except portage.exception.InvalidDependString:
+					pass
+			in_graph = self._depgraph._slot_pkg_map[
+				self._root].get(pkg.slot_atom)
+			if in_graph is None:
+				# Mask choices for packages which are not the highest visible
+				# version within their slot (since they usually trigger slot
+				# conflicts).
+				highest_visible, in_graph = self._depgraph._select_package(
+					self._root, pkg.slot_atom)
+				if pkg != highest_visible:
+					return False
+			elif in_graph != pkg:
+				# Mask choices for packages that would trigger a slot
+				# conflict with a previously selected package.
+				return False
+			return True
+
+		def _dep_expand(self, atom):
+			"""
+			This is only needed for old installed packages that may
+			contain atoms that are not fully qualified with a specific
+			category. Emulate the cpv_expand() function that's used by
+			dbapi.match() in cases like this. If there are multiple
+			matches, it's often due to a new-style virtual that has
+			been added, so try to filter those out to avoid raising
+			a ValueError.
+			"""
+			root_config = self._depgraph.roots[self._root]
+			orig_atom = atom
+			expanded_atoms = self._depgraph._dep_expand(root_config, atom)
+			if len(expanded_atoms) > 1:
+				non_virtual_atoms = []
+				for x in expanded_atoms:
+					if not portage.dep_getkey(x).startswith("virtual/"):
+						non_virtual_atoms.append(x)
+				if len(non_virtual_atoms) == 1:
+					expanded_atoms = non_virtual_atoms
+			if len(expanded_atoms) > 1:
+				# compatible with portage.cpv_expand()
+				raise portage.exception.AmbiguousPackageName(
+					[portage.dep_getkey(x) for x in expanded_atoms])
+			if expanded_atoms:
+				atom = expanded_atoms[0]
+			else:
+				null_atom = insert_category_into_atom(atom, "null")
+				null_cp = portage.dep_getkey(null_atom)
+				cat, atom_pn = portage.catsplit(null_cp)
+				virts_p = root_config.settings.get_virts_p().get(atom_pn)
+				if virts_p:
+					# Allow the resolver to choose which virtual.
+					atom = insert_category_into_atom(atom, "virtual")
+				else:
+					atom = insert_category_into_atom(atom, "null")
+			return atom
+
+		def aux_get(self, cpv, wants):
+			metadata = self._cpv_pkg_map[cpv].metadata
+			return [metadata.get(x, "") for x in wants]
+
+
+def ambiguous_package_name(arg, atoms, root_config, spinner, myopts):
+
+	if "--quiet" in myopts:
+		print "!!! The short ebuild name \"%s\" is ambiguous. Please specify" % arg
+		print "!!! one of the following fully-qualified ebuild names instead:\n"
+		for cp in sorted(set(portage.dep_getkey(atom) for atom in atoms)):
+			print "    " + colorize("INFORM", cp)
+		return
+
+	s = search(root_config, spinner, "--searchdesc" in myopts,
+		"--quiet" not in myopts, "--usepkg" in myopts,
+		"--usepkgonly" in myopts)
+	null_cp = portage.dep_getkey(insert_category_into_atom(
+		arg, "null"))
+	cat, atom_pn = portage.catsplit(null_cp)
+	s.searchkey = atom_pn
+	for cp in sorted(set(portage.dep_getkey(atom) for atom in atoms)):
+		s.addCP(cp)
+	s.output()
+	print "!!! The short ebuild name \"%s\" is ambiguous. Please specify" % arg
+	print "!!! one of the above fully-qualified ebuild names instead.\n"
+
+def insert_category_into_atom(atom, category):
+	alphanum = re.search(r'\w', atom)
+	if alphanum:
+		ret = atom[:alphanum.start()] + "%s/" % category + \
+			atom[alphanum.start():]
+	else:
+		ret = None
+	return ret
+
+def resume_depgraph(settings, trees, mtimedb, myopts, myparams, spinner):
+	"""
+	Construct a depgraph for the given resume list. This will raise
+	PackageNotFound or depgraph.UnsatisfiedResumeDep when necessary.
+	@rtype: tuple
+	@returns: (success, depgraph, dropped_tasks)
+	"""
+	skip_masked = True
+	skip_unsatisfied = True
+	mergelist = mtimedb["resume"]["mergelist"]
+	dropped_tasks = set()
+	while True:
+		mydepgraph = depgraph(settings, trees,
+			myopts, myparams, spinner)
+		try:
+			success = mydepgraph.loadResumeCommand(mtimedb["resume"],
+				skip_masked=skip_masked)
+		except depgraph.UnsatisfiedResumeDep, e:
+			if not skip_unsatisfied:
+				raise
+
+			graph = mydepgraph.digraph
+			unsatisfied_parents = dict((dep.parent, dep.parent) \
+				for dep in e.value)
+			traversed_nodes = set()
+			unsatisfied_stack = list(unsatisfied_parents)
+			while unsatisfied_stack:
+				pkg = unsatisfied_stack.pop()
+				if pkg in traversed_nodes:
+					continue
+				traversed_nodes.add(pkg)
+
+				# If this package was pulled in by a parent
+				# package scheduled for merge, removing this
+				# package may cause the the parent package's
+				# dependency to become unsatisfied.
+				for parent_node in graph.parent_nodes(pkg):
+					if not isinstance(parent_node, Package) \
+						or parent_node.operation not in ("merge", "nomerge"):
+						continue
+					unsatisfied = \
+						graph.child_nodes(parent_node,
+						ignore_priority=DepPrioritySatisfiedRange.ignore_soft)
+					if pkg in unsatisfied:
+						unsatisfied_parents[parent_node] = parent_node
+						unsatisfied_stack.append(parent_node)
+
+			pruned_mergelist = []
+			for x in mergelist:
+				if isinstance(x, list) and \
+					tuple(x) not in unsatisfied_parents:
+					pruned_mergelist.append(x)
+
+			# If the mergelist doesn't shrink then this loop is infinite.
+			if len(pruned_mergelist) == len(mergelist):
+				# This happens if a package can't be dropped because
+				# it's already installed, but it has unsatisfied PDEPEND.
+				raise
+			mergelist[:] = pruned_mergelist
+
+			# Exclude installed packages that have been removed from the graph due
+			# to failure to build/install runtime dependencies after the dependent
+			# package has already been installed.
+			dropped_tasks.update(pkg for pkg in \
+				unsatisfied_parents if pkg.operation != "nomerge")
+			mydepgraph.break_refs(unsatisfied_parents)
+
+			del e, graph, traversed_nodes, \
+				unsatisfied_parents, unsatisfied_stack
+			continue
+		else:
+			break
+	return (success, mydepgraph, dropped_tasks)
+
+def get_mask_info(root_config, cpv, pkgsettings,
+	db, pkg_type, built, installed, db_keys):
+	eapi_masked = False
+	try:
+		metadata = dict(izip(db_keys,
+			db.aux_get(cpv, db_keys)))
+	except KeyError:
+		metadata = None
+	if metadata and not built:
+		pkgsettings.setcpv(cpv, mydb=metadata)
+		metadata["USE"] = pkgsettings["PORTAGE_USE"]
+		metadata['CHOST'] = pkgsettings.get('CHOST', '')
+	if metadata is None:
+		mreasons = ["corruption"]
+	else:
+		eapi = metadata['EAPI']
+		if eapi[:1] == '-':
+			eapi = eapi[1:]
+		if not portage.eapi_is_supported(eapi):
+			mreasons = ['EAPI %s' % eapi]
+		else:
+			pkg = Package(type_name=pkg_type, root_config=root_config,
+				cpv=cpv, built=built, installed=installed, metadata=metadata)
+			mreasons = get_masking_status(pkg, pkgsettings, root_config)
+	return metadata, mreasons
+
+def show_masked_packages(masked_packages):
+	shown_licenses = set()
+	shown_comments = set()
+	# Maybe there is both an ebuild and a binary. Only
+	# show one of them to avoid redundant appearance.
+	shown_cpvs = set()
+	have_eapi_mask = False
+	for (root_config, pkgsettings, cpv,
+		metadata, mreasons) in masked_packages:
+		if cpv in shown_cpvs:
+			continue
+		shown_cpvs.add(cpv)
+		comment, filename = None, None
+		if "package.mask" in mreasons:
+			comment, filename = \
+				portage.getmaskingreason(
+				cpv, metadata=metadata,
+				settings=pkgsettings,
+				portdb=root_config.trees["porttree"].dbapi,
+				return_location=True)
+		missing_licenses = []
+		if metadata:
+			if not portage.eapi_is_supported(metadata["EAPI"]):
+				have_eapi_mask = True
+			try:
+				missing_licenses = \
+					pkgsettings._getMissingLicenses(
+						cpv, metadata)
+			except portage.exception.InvalidDependString:
+				# This will have already been reported
+				# above via mreasons.
+				pass
+
+		print "- "+cpv+" (masked by: "+", ".join(mreasons)+")"
+		if comment and comment not in shown_comments:
+			print filename+":"
+			print comment
+			shown_comments.add(comment)
+		portdb = root_config.trees["porttree"].dbapi
+		for l in missing_licenses:
+			l_path = portdb.findLicensePath(l)
+			if l in shown_licenses:
+				continue
+			msg = ("A copy of the '%s' license" + \
+			" is located at '%s'.") % (l, l_path)
+			print msg
+			print
+			shown_licenses.add(l)
+	return have_eapi_mask
+
+def show_mask_docs():
+	print "For more information, see the MASKED PACKAGES section in the emerge"
+	print "man page or refer to the Gentoo Handbook."
+
+def filter_iuse_defaults(iuse):
+	for flag in iuse:
+		if flag.startswith("+") or flag.startswith("-"):
+			yield flag[1:]
+		else:
+			yield flag
+
+def show_blocker_docs_link():
+	print
+	print "For more information about " + bad("Blocked Packages") + ", please refer to the following"
+	print "section of the Gentoo Linux x86 Handbook (architecture is irrelevant):"
+	print
+	print "http://www.gentoo.org/doc/en/handbook/handbook-x86.xml?full=1#blocked"
+	print
+
+def get_masking_status(pkg, pkgsettings, root_config):
+
+	mreasons = portage.getmaskingstatus(
+		pkg, settings=pkgsettings,
+		portdb=root_config.trees["porttree"].dbapi)
+
+	if not pkg.installed:
+		if not pkgsettings._accept_chost(pkg.cpv, pkg.metadata):
+			mreasons.append("CHOST: %s" % \
+				pkg.metadata["CHOST"])
+
+	if not pkg.metadata["SLOT"]:
+		mreasons.append("invalid: SLOT is undefined")
+
+	return mreasons
diff --git a/pym/_emerge/is_valid_package_atom.py b/pym/_emerge/is_valid_package_atom.py
new file mode 100644
index 000000000..bdfedc95b
--- /dev/null
+++ b/pym/_emerge/is_valid_package_atom.py
@@ -0,0 +1,16 @@
+import re
+
+try:
+	import portage
+except ImportError:
+	from os import path as osp
+	import sys
+	sys.path.insert(0, osp.join(osp.dirname(osp.dirname(osp.realpath(__file__))), "pym"))
+	import portage
+
+def is_valid_package_atom(x):
+	if "/" not in x:
+		alphanum = re.search(r'\w', x)
+		if alphanum:
+			x = x[:alphanum.start()] + "cat/" + x[alphanum.start():]
+	return portage.isvalidatom(x)