diff -r 0d612db7047c -r c59eb1560c44 mercurial/filemerge.py
--- a/mercurial/filemerge.py	Sun Oct 06 16:39:13 2019 -0400
+++ b/mercurial/filemerge.py	Sun Oct 06 16:55:18 2019 -0400
@@ -18,7 +18,10 @@
     nullid,
     short,
 )
-from .pycompat import open
+from .pycompat import (
+    getattr,
+    open,
+)
 
 from . import (
     encoding,