--- a/mercurial/dispatch.py Mon Oct 11 17:31:27 2021 +0200 +++ b/mercurial/dispatch.py Fri Oct 08 13:34:33 2021 -0700 @@ -253,7 +253,7 @@ status = -1 ret = _flushstdio(req.ui, err) - if ret: + if ret and not status: status = ret return status