diff -r bbcbb82e3589 -r 66f2cc210a29 mercurial/vfs.py
--- a/mercurial/vfs.py	Sun Oct 06 14:51:45 2019 -0400
+++ b/mercurial/vfs.py	Sun Oct 06 14:58:42 2019 -0400
@@ -14,6 +14,7 @@
 import threading
 
 from .i18n import _
+from .pycompat import setattr
 from . import (
     encoding,
     error,