diff -r 2abbf4750915 -r 90f2b9de30f2 mercurial/changegroup.py
--- a/mercurial/changegroup.py	Fri Apr 10 22:30:19 2015 -0400
+++ b/mercurial/changegroup.py	Fri Apr 10 23:34:06 2015 -0400
@@ -891,6 +891,7 @@
 
     finally:
         tr.release()
+        repo.ui.flush()
     # never return 0 here:
     if dh < 0:
         return dh - 1