diff -r a771ffc378a8 -r 49b6910217f9 mercurial/commandserver.py
--- a/mercurial/commandserver.py	Wed Dec 09 00:00:19 2020 -0800
+++ b/mercurial/commandserver.py	Thu Dec 10 13:51:56 2020 +0530
@@ -355,18 +355,7 @@
         )
 
         try:
-            err = None
-            try:
-                status = self._dispatchcommand(req)
-            except error.StdioError as e:
-                status = -1
-                err = e
-
-            retval = dispatch.closestdio(req.ui, err)
-            if retval:
-                status = retval
-
-            ret = status & 255
+            ret = self._dispatchcommand(req) & 255
             # If shutdown-on-interrupt is off, it's important to write the
             # result code *after* SIGINT handler removed. If the result code
             # were lost, the client wouldn't be able to continue processing.