Why is mercurial version always 1.3.1 even though I installed 1.6.4?

I ran pip uninstall mercurial Mac OSX 10.6.6, with and without sudo, in my virtualenv, and removed every trace of hg or mercurial on my machine. I tried re-installing like so:

• pip install mercurial==1.6.4
• http://mercurial.berkwood.com开发者_开发百科/ where I downloaded a Mac-specific version of 1.6.4

All efforts yielded the same from hg --version:

Mercurial Distributed SCM (version 1.3.1)

Copyright (C) 2005-2009 Matt Mackall and others This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

Is this a bug? Shouldn't it display 1.6.4 instead of 1.3.1? If not, why?

The hg binary is just a thin wrapper around the mercurial Python module. It sounds like all you did was remove the old hg binary but not the old mercurial Python module, so the new install is picking up the old modules.

You can see where the modules are installed with python -c 'import mercurial; print mercurial.__file__'