Revive commands.dispatch as a simple way to call hg from other pythons scripts. This was already used by hg-ssh and others and is really convenient if you just want a native equivalent of calling the command line version.

#!/bin/sh

hg init a
echo a > a/a
hg --cwd a ci -A -m a
hg clone a b
echo b > b/b
hg --cwd b ci -A -m b
chmod 100 a/.hg/store
hg --cwd b push ../a
chmod 700 a/.hg/store