Pip 20.3.x may cause indefinite searching for packages when installing a package.

[ryuheechul]

What did you want to do?

pip install [my-private-package]

Output

Sorry that I'm unable to provide the output but it was about searching which packages to resolve and it still couldn't finish after over a whole night!

Additional information

after I switch pip to 20.2 it didn't run forever but instead, it failed fast with this message:

ERROR: After October 2020 you may experience errors when installing or updating packages. This is because pip will change the way that it resolves dependency conflicts.

We recommend you use --use-feature=2020-resolver to test your packages with the new resolver before it becomes the default.

requests 2.23.0 requires urllib3!=1.25.0,!=1.25.1,<1.26,>=1.21.1, but you'll have urllib3 1.26.2 which is incompatible.

Which gave me enough clue to fix my package's dependency.

Also maybe this issue, #9233 is somehow related?

Dear maintainers, even though I'm reporting this issue I'm not much of a python guy to help you with well-prepared details at the moment, but I will try to answer your questions if you have any.

[megfordpix]

I just encountered this issue on Friday. I had to pin some of our codebase's dependencies to specific versions that the resolver asked for, and I had to install the pip master branch using python -m pip install -U "pip @ https://github.com/pypa/pip/archive/master.zip"

Can the maintainers tell me when the next release goes out? I'm fine with pulling in pip from master for now, but want to keep an eye on it and revert to the standard pip build when the fix for this is released. Thanks!

[ryuheechul]

in the meantime, to share how I worked around the issue (especially in case you use pipx), https://gist.github.com/ryuheechul/c2a71d53cb6c2ec7827b15ab8843add1#choose-different-pip-version-for-pipx

[pradyunsg]

Duplicate of #9187. There'll be a bugfix release later this week.