FYI black, isort and flake8 can be run once per repository instead of per package, that would avoid duplicating a ton of lines in tox (and also work)

Sure, but I want to produce a scenario as similar as possible to a scenario where there are multiple tox.ini files, one per package.

Lint tests take ~14 minutes right now: https://github.com/open-telemetry/opentelemetry-python-contrib/actions/runs/8839570393/job/24273211949

This PR speeds up this process to ~2 minutes: https://github.com/open-telemetry/opentelemetry-python-contrib/actions/runs/8862990640

FYI black, isort and flake8 can be run once per repository instead of per package, that would avoid duplicating a ton of lines in tox (and also work)

Sure, but I want to produce a scenario as similar as possible to a scenario where there are multiple tox.ini files, one per package.

I see that, I would had hoped to make lint faster by using faster tools before splitting stuff though.

FYI black, isort and flake8 can be run once per repository instead of per package, that would avoid duplicating a ton of lines in tox (and also work)

Sure, but I want to produce a scenario as similar as possible to a scenario where there are multiple tox.ini files, one per package.

I see that, I would had hoped to make lint faster by using faster tools before splitting stuff though.

Sure, we can move to another tool later, this does not introduce anyting new that needs further CI testing and already makes a huge difference.

Would be nice to sort packages in the matrix though

Right, I just sorted them ✌️