diff -r bbcbb82e3589 -r 66f2cc210a29 mercurial/phases.py
--- a/mercurial/phases.py	Sun Oct 06 14:51:45 2019 -0400
+++ b/mercurial/phases.py	Sun Oct 06 14:58:42 2019 -0400
@@ -113,6 +113,7 @@
     nullrev,
     short,
 )
+from .pycompat import setattr
 from . import (
     error,
     pycompat,