Fix tmp_path regression introduced in 7.3.0

[nicoddemus]

The problem is that we would loop over all directories of the basetemp directory searching for dead symlinks, for each test, which would compound over the test session run.

Doing the cleanup just once, at the end of the session, fixes the problem.

Fix #10896

[nicoddemus]

To test this, I wrote this file:

import pytest

DATA = "0" * 1 * 1024 * 1024


@pytest.mark.parametrize("i", range(2000))
def test1(tmp_path, i):
    tmp_path.joinpath("hello.txt").write_text(DATA)

In pytest-7.3.0, I get:

2000 passed in 314.96s (0:05:14)

(You can see each test taking longer and longer).

In this branch I get:

2000 passed in 15.21s

I couldn't think of a test for this, given the regression is circumstantial.

[The-Compiler]

@nicoddemus Any chance you could push the tags to your repo so I can easily test this? Right now I get:

ERROR: Cannot install -r /home/florian/proj/qutebrowser/git/misc/requirements/requirements-tests.txt (line 33) and pytest 6.0.1.dev2203+g2d01dbd0 (from git+https://github.com/nicoddemus/pytest.git@tmp-path-regression) because these package versions have conflicting dependencies.

The conflict is caused by:
    The user requested pytest 6.0.1.dev2203+g2d01dbd0 (from git+https://github.com/nicoddemus/pytest.git@tmp-path-regression)
    pytest-bdd 6.1.1 depends on pytest>=6.2.0

Something like this should do:

git fetch upstream --tags
git push origin --tags

[The-Compiler]

I got it to work via SETUPTOOLS_SCM_PRETEND_VERSION=7.3.1 🤷

Seems to work fine, thanks for the investigation and fix! Down from 1h 5min to 24 minutes again now.

[nicoddemus]

Ahh sorry, just saw it now. Anyway I pushed the tags, glad you could work around that.