--- a/hgext3rd/evolve/legacy.py	Sun Oct 01 15:32:29 2017 +0530
+++ b/hgext3rd/evolve/legacy.py	Tue Oct 03 22:51:00 2017 +0800
@@ -129,16 +129,16 @@
                     del oldmark['reason']  # unused until then
                     oldobject = str(oldmark.pop('object'))
                     oldsubjects = [str(s) for s in oldmark.pop('subjects', [])]
-                    LOOKUP_ERRORS = (error.RepoLookupError, error.LookupError)
+                    lookup_errors = (error.RepoLookupError, error.LookupError)
                     if len(oldobject) != 40:
                         try:
                             oldobject = repo[oldobject].node()
-                        except LOOKUP_ERRORS:
+                        except lookup_errors:
                             pass
                     if any(len(s) != 40 for s in oldsubjects):
                         try:
                             oldsubjects = [repo[s].node() for s in oldsubjects]
-                        except LOOKUP_ERRORS:
+                        except lookup_errors:
                             pass
 
                     oldmark['date'] = '%i %i' % tuple(oldmark['date'])