[IPython-dev] Weird PYTHONPATH, etc. issue

[Fernando Perez]

On Wed, Sep 19, 2012 at 2:49 PM, David Warde-Farley
<d.warde.farley at gmail.com> wrote:
> It's only when IPython spawns another process that things fall on
> their face. Namely, the client remains 0.14.dev but the server imports
> 0.13, so the client is sending messages that the server can't
> decipher, I get a lot of "Invalid signature" and "malformed message"
> stuff.

Yup.  Just a few days ago I had to fix this very problem for a
colleague (though in her case, caused by a system-wide EPD install
where setuptools was overriding any local PYTHONPATH configuration).
After some frustration, I learned of the file 'usercustomize.py':

http://docs.python.org/library/site.html

Put a file with this name *anywhere* in your PYTHONPATH, and fix
sys.path manually in there to reorder things as needed, e.g.

sys.path = [os.environ['HOME']+'.local/lib/python2.7/site-packages/'] + sys.path

and you're done.

HTH,

f