In order to push changes to a mercurial repo running on media temple you'll need to add to their default instructions from here. They mention adding PATH to ~/.bash_profile whereas on ssh ~/.bashrc is used. See here.

echo -e 'export PYTHONPATH=${HOME}/lib/python:$PYTHONPATH\nexport PATH=${HOME}/bin:$PATH' >> ~/.bashrc

http://forum.webfaction.com/viewtopic.php?id=946 http://kb.mediatemple.net/questions/1639/Installing+Mercurial+on+the+(gs)+Grid-Service