Ah I just hit an interesting problem with Mercurial. I had a repository which had been created with a recent version however I had to restore it from a backup onto another machine however I couldn’t commit to it as it’s format wasn’t supported:
$ hg st
abort: requirement ‘dotencode’ not supported!
The reason is that the dotencode format was only introduced into mercurial in version 1.7 so if you’re running an earlier version then you’ll get this error. Ok so upgrade – problem is that according to apt I had the latest version – 1.6.3 – erm nope thats not the latest.
Thankfully the fix is simple, all you need is to ass the correct repository first before installing the latest version
sudo add-apt-repository ppa:mercurial-ppa/releases
sudo apt-get update
sudo apt-get install mercurial
Once you’ve done that then you’ll find mercurial will work again as expected.
Peter Mount's Blog 