diff -r a5de21c9e370 -r a86d21e70b2b mercurial/httppeer.py
--- a/mercurial/httppeer.py	Tue Aug 21 15:33:11 2018 -0700
+++ b/mercurial/httppeer.py	Wed Sep 12 09:58:23 2018 -0700
@@ -802,7 +802,8 @@
             return True
 
         # Other concepts.
-        if name in ('bundle2',):
+        # TODO remove exchangev2 once we have a command implemented.
+        if name in ('bundle2', 'exchangev2'):
             return True
 
         # Alias command-* to presence of command of that name.