mercurial/bundle2.py

--- a/mercurial/bundle2.py	Wed Jun 01 15:48:38 2016 -0500
+++ b/mercurial/bundle2.py	Wed Jun 01 21:40:52 2016 +0200
@@ -1453,7 +1453,7 @@
     # Trigger a transaction so that we are guaranteed to have the lock now.
     if op.ui.configbool('experimental', 'bundle2lazylocking'):
         op.gettransaction()
-    if heads != op.repo.heads():
+    if sorted(heads) != sorted(op.repo.heads()):
         raise error.PushRaced('repository changed while pushing - '
                               'please try again')