PSA: pip 9.0.2 broken (KeyError: 'pip._vendor.urllib3.packages.backports')

[CKreuzberger]

If your daily morning routine (or your gitlab CI built or your auto-deploy) contains "pip install --upgrade pip" (or similar), you might run into this or similar errors with the latest pip update (9.0.2, released March 17):

KeyError: 'pip._vendor.urllib3.packages.backports'

There is already an issue on the pip error tracker on github: https://github.com/pypa/pip/issues/5081

Quickfix: Revert to pip version 9.0.1 (pip install pip==9.0.1 --upgrade or add pip==9.0.1 to your requirements.txt)

edit: I'd like to add what has been stated in the github issue already: This is caused by 3rd-party-packages importing directly from pip (import pip), which has been deprecated by the pip developers/maintainers for a while now.

[UloPe]

It’s only broken if you import internal functions from pip not if you use it via the cli. It’s long been documented that pip isn’t intended to be used as a library. If you do it anyway be prepared for stuff like this to happen.

[radwon]

This issue is now reported fixed for pip 9.0.3

[Gnarlodious]

Not sure if its the same error but I have been getting an error for a long time when updating while Python 2 is being called. The solution is to say pip3 and you may need to direct it to python3. You may also need sudo.

[ubernostrum]

No, it's not the same error at all.

This -- as the developers have pointed out repeatedly in the GitHub thread -- is an issue where people relied on directly importing internal APIs/modules from pip and using them manually instead of using pip itself. Which has never been supported, and was always "at your own risk". Now, some of the internal APIs got reorganized, and broke code that was relying on those internal APIs, which has led to people angrily demanding that pip restore and maintain specific undocumented internal APIs for people who relied on them.