When backtracking due to an unsatisfied dependency, show a normal unsatisfied

dependency message for the given atom. Thanks to Thomas Sachau
<tommy@gentoo.org> for reporting.

svn path=/main/trunk/; revision=13852

1 files changed, 49 insertions, 3 deletions

diff --git a/pym/_emerge/depgraph.py b/pym/_emerge/depgraph.py
index dc74b3669..527b2f9fa 100644
--- a/pym/_emerge/depgraph.py
+++ b/pym/_emerge/depgraph.py
@@ -276,6 +276,8 @@ class depgraph(object):
 			'--debug' not in self._frozen_config.myopts:
 			return
 
+		# In order to minimize noise, show only the highest
+		# missed update from each SLOT.
 		missed_updates = {}
 		for pkg, mask_reasons in \
 			self._dynamic_config._runtime_pkg_mask.iteritems():
@@ -284,24 +286,63 @@ class depgraph(object):
 				# want to show available updates.
 				continue
 			if pkg.slot_atom in missed_updates:
-				other_pkg, parent_atoms = missed_updates[pkg.slot_atom]
+				other_pkg, mask_type, parent_atoms = \
+					missed_updates[pkg.slot_atom]
 				if other_pkg > pkg:
 					continue
 			for mask_type, parent_atoms in mask_reasons.iteritems():
 				if not parent_atoms:
 					continue
-				missed_updates[pkg.slot_atom] = (pkg, parent_atoms)
+				missed_updates[pkg.slot_atom] = (pkg, mask_type, parent_atoms)
 				break
 
 		if not missed_updates:
 			return
 
+		missed_update_types = {}
+		for pkg, mask_type, parent_atoms in missed_updates.itervalues():
+			missed_update_types.setdefault(mask_type,
+				[]).append((pkg, parent_atoms))
+
+		self._show_missed_update_slot_conflicts(
+			missed_update_types.get("slot conflict"))
+
+		self._show_missed_update_unsatisfied_dep(
+			missed_update_types.get("missing dependency"))
+
+	def _show_missed_update_unsatisfied_dep(self, missed_updates):
+
+		if not missed_updates:
+			return
+
+		write = sys.stderr.write
+
+		for pkg, parent_atoms in missed_updates:
+
+			write("\n!!! The following update has been skipped " + \
+				"due to unsatisfied dependencies:\n\n")
+
+			write(str(pkg.slot_atom))
+			write("\n")
+
+			for parent, atom in parent_atoms:
+				# TODO: Account for which $ROOT the atom applies to.
+				self._show_unsatisfied_dep(parent.root, atom, myparent=parent)
+				write("\n")
+
+		sys.stderr.flush()
+
+	def _show_missed_update_slot_conflicts(self, missed_updates):
+
+		if not missed_updates:
+			return
+
 		msg = []
 		msg.append("\n!!! One or more updates have been skipped due to " + \
 			"a dependency conflict:\n\n")
 
 		indent = "  "
-		for pkg, parent_atoms in missed_updates.itervalues():
+		for pkg, parent_atoms in missed_updates:
 			msg.append(str(pkg.slot_atom))
 			msg.append("\n\n")
 
@@ -1932,6 +1973,11 @@ class depgraph(object):
 			traversed_nodes.add(node)
 			msg.append('(dependency required by "%s" [%s])' % \
 				(colorize('INFORM', str(node.cpv)), node.type_name))
+
+			if node not in self._dynamic_config.digraph:
+				# The parent is not in the graph due to backtracking.
+				break
+
 			# 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.