Rebuild when build-time/run-time deps are upgraded.

pym/_emerge/Dependency.py

Index: pym/_emerge/Dependency.py
diff --git a/pym/_emerge/Dependency.py b/pym/_emerge/Dependency.py
index 63b2a1b12bc7aa7839005e261a40dfa01e2bffd5..d5d519d97dec5550ceb52d36169980f804f2206d 100644
--- a/pym/_emerge/Dependency.py
+++ b/pym/_emerge/Dependency.py
@@ -5,11 +5,16 @@ from _emerge.DepPriority import DepPriority
 from _emerge.SlotObject import SlotObject
 class Dependency(SlotObject):
 	__slots__ = ("atom", "blocker", "child", "depth",
-		"parent", "onlydeps", "priority", "root")
+		"parent", "onlydeps", "priority", "root",
+		"collapsed_parent", "collapsed_priority")
 	def __init__(self, **kwargs):
 		SlotObject.__init__(self, **kwargs)
 		if self.priority is None:
 			self.priority = DepPriority()
 		if self.depth is None:
 			self.depth = 0
+		if self.collapsed_parent is None:
+			self.collapsed_parent = self.parent
+		if self.collapsed_priority is None:
+			self.collapsed_priority = self.priority