diff -r 5542bc9125c9 -r 9683dfb6f13a mercurial/commandserver.py
--- a/mercurial/commandserver.py	Sun Jan 18 18:43:23 2015 +0900
+++ b/mercurial/commandserver.py	Wed Nov 07 22:37:51 2018 +0900
@@ -320,8 +320,8 @@
         # redirect stdio to null device so that broken extensions or in-process
         # hooks will never cause corruption of channel protocol.
         with procutil.protectedstdio(ui.fin, ui.fout) as (fin, fout):
+            sv = server(ui, self.repo, fin, fout)
             try:
-                sv = server(ui, self.repo, fin, fout)
                 return sv.serve()
             finally:
                 sv.cleanup()