mercurial/debugcommands.py

--- a/mercurial/debugcommands.py	Sun Oct 06 13:17:19 2019 -0400
+++ b/mercurial/debugcommands.py	Sun Oct 06 13:28:56 2019 -0400
@@ -32,6 +32,7 @@
     nullrev,
     short,
 )
+from .pycompat import open
 from . import (
     bundle2,
     changegroup,