New system. No breaking in, just putting files in /etc/mercurial-server
# WARNING: when these hooks run they will entirely destroy and rewrite
# ~/.ssh/authorized_keys
[hooks]
changegroup.aaaaa_update = hg update -C default > /dev/null
changegroup.aaaab_purge = hg purge --all > /dev/null
changegroup.refreshauth = /etc/mercurial-server/refresh-auth