Revert one more change from bug #337178: parent_atoms is supposed
to refer to the new pkg, not the one to_be_masked.
diff --git a/pym/_emerge/depgraph.py b/pym/_emerge/depgraph.py
index 54e412a..50aefda 100644
--- a/pym/_emerge/depgraph.py
+++ b/pym/_emerge/depgraph.py
@@ -899,7 +899,7 @@
 						to_be_masked = existing_node
 
 						parent_atoms = \
-							self._dynamic_config._parent_atoms.get(to_be_masked, set())
+							self._dynamic_config._parent_atoms.get(pkg, set())
 						if parent_atoms:
 							conflict_atoms = self._dynamic_config._slot_conflict_parent_atoms.intersection(parent_atoms)
 							if conflict_atoms: