[IPython-dev] Weird PYTHONPATH, etc. issue

[David Warde-Farley]

On Wed, Sep 19, 2012 at 5:30 PM, Thomas Kluyver <takowl at gmail.com> wrote:

> I'm sure it's possible - for instance, the parent process could
> serialise its sys.path, to be recreated in the child process. I'm not
> sure whether we want to introduce that sort of measure, though - the
> situation where 'import IPython' doesn't get the IPython version
> you're using seems a bit pathological.

That isn't the situation, not quite. In a normal Python REPL:

>>> import IPython
>>> IPython.__version__
'0.13'

In IPython launched from ~/.local/bin/ipython (by virtue of
pkg_resources.load_entry_point):

In [1]: import IPython

In [2]: IPython.__version__
Out[2]: '0.14.dev'

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.

David