New UnexpectedOutput exception to catch server errors in localrepo.stream_in If the unexpected is a string, the empty string will be mentioned, and long strings are cut to at most 400 chars.

#!/bin/sh

mkdir t
cd t
hg init
echo "invalid" > .hg/hgrc
hg status 2>&1 |sed -e "s:/.*\(/t/.*\):...\1:"