depgraph: fix possible REQUIRED_USE KeyError

This goes with commit a0961708ced50c90497811058eda6f4513d2986d.

diff --git a/pym/_emerge/depgraph.py b/pym/_emerge/depgraph.py
index 301b2521085088ef121c414eb627ae3b056dfeca..2296aa0012130f685ab79f39c8e4f4c03f6d46fc 100644 (file)
--- a/pym/_emerge/depgraph.py
+++ b/pym/_emerge/depgraph.py
@@ -3114,7 +3114,7 @@ class depgraph(object):
                                        if untouchable_flags.intersection(involved_flags):
                                                continue
 
-                                       required_use = myparent.metadata["REQUIRED_USE"]
+                                       required_use = myparent.metadata.get("REQUIRED_USE")
                                        required_use_warning = ""
                                        if required_use:
                                                old_use = self._pkg_use_enabled(myparent)