diff -r 0d612db7047c -r c59eb1560c44 mercurial/debugcommands.py
--- a/mercurial/debugcommands.py	Sun Oct 06 16:39:13 2019 -0400
+++ b/mercurial/debugcommands.py	Sun Oct 06 16:55:18 2019 -0400
@@ -32,7 +32,10 @@
     nullrev,
     short,
 )
-from .pycompat import open
+from .pycompat import (
+    getattr,
+    open,
+)
 from . import (
     bundle2,
     changegroup,