Running the full test suite on Windows can affect system Python

Environment

• pip version: 19.3.1 and master
• Python version: 3.8.1
• OS: Windows 10

Description Copied from here:

Oh, if additional arguments are needed to run pip’s tests out of the box, that’s not right.

The commands to run the tests on Windows (from the CI config) are:

tox -e py -- -m unit -n auto
tox -e py -- -m integration -n auto

Those work. But just tox -e py produces loads of errors, suggesting that there are tests that are marked as neither “unit” nor “integration” that are failing on Windows. Worse, after running the incorrect command, I found masses of unexpected packages installed in my system Python! (I was running tox from a venv created just for testing pip, so everything should have been 100% isolated from the system install. It was bad enough that reinstalling my system Python was the easiest fix.

I’ll make this comment into a separate issue, but honestly I don’t want to spend a lot of time fighting the test suite into submission on Windows, particularly if it involves trashing my system Python on a regular basis 🙁 So if anyone else wants to pick this up, they are welcome to do so.

[pfmoore]

OK, I’ve run the test suite multiple times now, and never been able to reproduce the issue. I’m going to put it down as user error, and close the issue.

[pfmoore]

That’s an interesting idea, thanks. I’ll look into that (but I want to check locally that I didn’t do something really dumb first 🙂).