--- a/mercurial/commands.py	Tue Oct 20 15:52:42 2015 +0200
+++ b/mercurial/commands.py	Tue Oct 20 15:53:07 2015 +0200
@@ -6566,7 +6566,7 @@
             if isinstance(gen, bundle2.unbundle20):
                 tr = repo.transaction('unbundle')
                 try:
-                    op = bundle2.applybundle(repo, gen, tr)
+                    op = bundle2.applybundle(repo, gen, tr, source='unbundle')
                     tr.close()
                 except error.BundleUnknownFeatureError as exc:
                     raise error.Abort(_('%s: unknown bundle feature, %s')