pip install won't install a package if you are in a directory with an egg-info of that package and version.

[tomprince]

So, if I do python setup.py sdist && pip install dist/<package>, it won't actually install the package, because that creates an egg-info in the current directory.

This appears to have been introduced between 7.0.2 and 7.0.3.

The underlying issue here is perhaps the same as #2926

[dstufft]

Hrm, I don't think this could have been introduced in 7.0.3 since there was only a minor unrelated fix between 7.0.2 and 7.0.3.

Did you actually use pip install or did you use python -m pip?

[tomprince]

I was actually seeing it in tox.

[dstufft]

I think tox actually calls python -m pip, and if I recall when you execute python -m pip instead of pip Python itself adds . to sys.path. When pip (via pkg_resources) inspects the sys.path it would then see the installed distribution.

If that's right, I'm not sure what we should do, we could modify sys.path to remove .... but is that the right thing to do?

[dstufft]

Closing this, the fundamental issue is that the egg-info is on the sys.path and we don't have a way to determine that it isn't supposed to be.