diff -r 361a7444bc41 -r b1e51ef4e536 mercurial/bundle2.py
--- a/mercurial/bundle2.py	Tue Jul 07 22:00:02 2020 +0200
+++ b/mercurial/bundle2.py	Wed Jul 08 00:15:15 2020 +0200
@@ -2208,7 +2208,7 @@
         b'remote repository changed while pushing - please try again '
         b'(%s is %s expected %s)'
     )
-    for expectedphase, nodes in enumerate(phasetonodes):
+    for expectedphase, nodes in pycompat.iteritems(phasetonodes):
         for n in nodes:
             actualphase = phasecache.phase(unfi, cl.rev(n))
             if actualphase != expectedphase: