Idea: Check for packages with 2 installed versions

[msabramo]

If you end up with 2 egg-infos or dist-infos, weird stuff happens. IIRC, pip reports one of them only and it's not necessarily the one that gets loaded when code tries to import.

Folks sometimes run into this at my work where pip freeze tells them a new version is installed but the system exhibits behavior of the old version. Usually in this case, I advise doing pip uninstall twice, they look at me like "Seriously?", and then it fixes their problem.

This was the motivation behind my pip install -e PR #1552. But I don't know I there are other ways to get into that situation.

Maybe a pip check command? And maybe a pip freeze would do this check as well?

[tritium21]

2 installed versions is not something generally supported in python (except with eggs, and pip does not deal with eggs). Unless I am missing something here...

[qwcode]

yes, I agree this can happen on occasion, and it causes problems. there's an open PR for pip check already related to checking for conflicts or missing dependencies, but this makes sense as an additional check.

[msabramo]

@qwcode: I assume you're referring to #1001 ?

[qwcode]

@msabramo yes

[dstufft]

Closing this. I believe that we've fixed the underlying problem that was causing this to happen making such a check no longer needed. If you run into this problem again please open a new issue for it.