--- a/mercurial/wireprotov2peer.py	Mon Oct 08 17:00:16 2018 -0700
+++ b/mercurial/wireprotov2peer.py	Fri Oct 05 09:23:06 2018 -0700
@@ -325,6 +325,8 @@
                 raise e
 
             return
+        elif action == 'noop':
+            return
 
         if frame.requestid not in self._requests:
             raise error.ProgrammingError(