This is more of a reminder for me.
Several times recently I’ve run into problems where files in a MultiUser Mercurial repository on a linux host are getting the wrong group permissions. If you properly set the group sticky bit when you first setup the repo, you won’t have this issue. To fix the issue, I needed to set the sticky bit on every directory in the .hg/store directory recursively.
find /path/to/.hg/store/ -type d -exec chmod g+s {} \;