$ cat .hg/hgrc [hooks] pretxncommit.msglen = test `hg tip --template {desc} | wc -c` -ge 10 $ echo a > a $ hg add a $ hg commit -A -m 'too short' transaction abort! rollback completed abort: pretxncommit.msglen hook exited with status 1 $ hg commit -A -m 'long enough'