diff -r dd35abc409ee -r 119e1c6be1ce mercurial/bundle2.py
--- a/mercurial/bundle2.py	Thu Aug 10 09:37:50 2017 -0700
+++ b/mercurial/bundle2.py	Wed Aug 09 17:01:21 2017 +0200
@@ -373,7 +373,7 @@
         msg = ['bundle2-input-bundle:']
         if unbundler.params:
             msg.append(' %i params' % len(unbundler.params))
-        if op.gettransaction is None or op.gettransaction is _notransaction:
+        if op._gettransaction is None or op._gettransaction is _notransaction:
             msg.append(' no-transaction')
         else:
             msg.append(' with-transaction')