On Fri, Apr 13, 2012 at 5:50 AM, Andrea Crotti <andrea.crotti.0@gmail.com> wrote:
I'm trying to understand exactly when running python setup.py develop is
necessary to make sure that everything will work as expected.

After some thinking I came to the conclusion that all the information
that should be kept up-to-date is in the .egg-info directory. So if I
understood correctly means that I only need to run "develop" once and
"egg_info" every time I need to update.

Not quite correct: if you add new scripts to your project, then you would also need to run develop in that case, to install the new scripts.

And as a related topic we would really like to avoid cluttering the
directories with these egg-info directories, and with my script I know
write them in another known directory.

But what happens if pkg_resources or similar try to use these
information and don't find the egg-info because it's not where it's
supposed to be?

It will either fail to find the package, or add some other directory to sys.path, possibly messing various things up in the process.  Using "develop" with a relocated egg-info directory should actually give you an error message; I'm kind of surprised that it's not giving you an error message, unless perhaps you're waiting until *after* you've run "develop" to move the .egg-info.  (Either that or I didn't consider that anybody would want to use develop with a manually-relocated .egg-info, and thus didn't put in the error checking.)