diff -r c2e284cee333 -r eef9a2d67051 mercurial/subrepo.py
--- a/mercurial/subrepo.py	Sun Oct 06 13:17:19 2019 -0400
+++ b/mercurial/subrepo.py	Sun Oct 06 13:28:56 2019 -0400
@@ -19,6 +19,7 @@
 import xml.dom.minidom
 
 from .i18n import _
+from .pycompat import open
 from . import (
     cmdutil,
     encoding,