diff -r ab04ce6f0674 -r 9d5ddf55415b mercurial/localrepo.py
--- a/mercurial/localrepo.py	Fri Oct 12 17:34:45 2018 -0400
+++ b/mercurial/localrepo.py	Tue Oct 09 21:53:21 2018 -0400
@@ -708,6 +708,7 @@
     """Resolve opener options specific to revlogs."""
 
     options = {}
+    options[b'flagprocessors'] = {}
 
     if b'revlogv1' in requirements:
         options[b'revlogv1'] = True