pytest 7.2.0 regression: 'py' is not a package - but py library is installed

[amezin]

https://github.com/ddterm/gnome-shell-extension-ddterm/actions/runs/3330468879/jobs/5509011844

py is installed in system site packages, pytest and pytest-html are installed in a virtualenv (system site packages are enabled).

Seems that in this case py module from pytest takes precedence over pylib from system site packages (and breaks pytest-html).

Everything works fine with pytest==7.1.3, fails with pytest==7.2.0.

[nicoddemus]

@amezin just so we understand, why do you have py in system packages?

A workaround is to install py in your virtual environment.

[amezin]

I have py in system packages because I install tox system-wide, and tox depends on py. And then I use tox to create the virtualenv.

And I don't want to turn off system site packages because I also need PyGObject. Currently it's installed using distro's package manager. If installing with pip, it will need multiple dependencies - GCC, -dev packages.

[nicoddemus]

I see.

Can you check if installing py explicitly in your virtualenv solves the issue for you?

[asottile]

you'll likely need --ignore-installed such that you get a copy of py inside your virtualenv -- though admittedly system-site-packages is already playing with fire so...

[amezin]

Yes, when py is installed into the virtualenv (with --ignore-installed) it works: https://github.com/ddterm/gnome-shell-extension-ddterm/actions/runs/3380104688/jobs/5612522131

[nicoddemus]

Thanks @amezin for following up. 👍

[The-Compiler]

Not sure if we should close this? If there is a way for our stub to deal with this (maybe check if py is importable or something?), I feel like we should, no?

[asottile]

it's too late at that point -- the module has already been shadowed

[amezin]

Couldn't it be solved with import hooks?

[asottile]

afaict there's nothing to "solve" -- using --system-site-packages in general is a bad idea and you've got a solution already

[sirex]

It looks, that py was removed as pytest dependency and py was included into pytest itself:

19dda7c

I was importing py mainly for type annotations for tmpdir, but to fix this, decided to replace tmpdir with tmp_path, which uses native pathlib.Path.