reverse sense of return value from python hooks. old scheme (False/None/0/'' == fail) made coding style unnatural, did not allow use of mercurial commands as hooks. new scheme (False/None/0 == pass) is pythonic, does not require peculiar "return True" at ends of hooks, allows hooks like this: [hooks] # update working dir after push into this repo changegroup.update = python:mercurial.commands.update

#!/bin/sh

hg init
echo 123 > a
hg add a
hg commit -m "first" -d "1000000 0" a
mkdir sub
echo 321 > sub/b
hg add sub/b
hg commit -m "second" -d "1000000 0" sub/b
cat sub/b
hg co 0
cat sub/b 2>/dev/null || echo "sub/b not present"
ls sub 2>/dev/null || echo "sub not present"

true