--- a/mercurial/dispatch.py	Sat Apr 15 12:58:06 2017 +0900
+++ b/mercurial/dispatch.py	Sat Apr 15 13:02:34 2017 +0900
@@ -255,7 +255,6 @@
             if '--debugger' in req.args:
                 traceback.print_exc()
                 debugmortem[debugger](sys.exc_info()[2])
-            ui.traceback()
             raise
 
     return _callcatch(ui, _runcatchfunc)