--- a/mercurial/exchange.py	Mon May 18 13:23:14 2015 -0500
+++ b/mercurial/exchange.py	Mon May 18 15:33:21 2015 -0500
@@ -1315,7 +1315,7 @@
                         def recordout(output):
                             r.newpart('output', data=output, mandatory=False)
                 tr.close()
-            except Exception, exc:
+            except BaseException, exc:
                 exc.duringunbundle2 = True
                 if captureoutput and r is not None:
                     parts = exc._bundle2salvagedoutput = r.salvageoutput()