This extension is not distributed with Mercurial.
Author: Ryan Seto
Action Log provides a Mercurial (hg) hook that is intended to help keep track of a remote repository's state when multiple people have access to update, such as a website that is a Mercurial repository with it's own working directory.
Edit your repository's hgrc file. It is located in the .hg folder.
Add the following line in the [hooks] section:
[hooks] update.actionlog = python:/path/to/actionlog.py:updatehook
Now, when you update your repository with the "hg update" command, actionlog will append to a log file called action.log in the .hg folder.