diff -r 6b81309d15a7 -r df0ce98c882f mercurial/exchange.py
--- a/mercurial/exchange.py	Thu Apr 23 14:54:45 2015 +0100
+++ b/mercurial/exchange.py	Thu Apr 23 16:36:18 2015 +0100
@@ -1297,11 +1297,15 @@
                 tr.hookargs['source'] = source
                 tr.hookargs['url'] = url
                 tr.hookargs['bundle2'] = '1'
-                r = bundle2.processbundle(repo, cg, lambda: tr).reply
-                if r is not None:
-                    repo.ui.pushbuffer(error=True, subproc=True)
-                    def recordout(output):
-                        r.newpart('output', data=output, mandatory=False)
+                op = bundle2.bundleoperation(repo, lambda: tr)
+                try:
+                    r = bundle2.processbundle(repo, cg, op=op)
+                finally:
+                    r = op.reply
+                    if r is not None:
+                        repo.ui.pushbuffer(error=True, subproc=True)
+                        def recordout(output):
+                            r.newpart('output', data=output, mandatory=False)
                 tr.close()
             except Exception, exc:
                 exc.duringunbundle2 = True