Excessive /tmp size after running tox test suite

[mimre25]

Issue

I've recently contributed to tox for the first time (see #3272), and I've noticed that my /tmp/pytest-of-$USER got quite big.
I've started a discussion in pytest-dev/pytest#12283 and dug a bit into it.
Ultimately, I found out that the tox' test suite uses a of that temporary storage.

Just now, I've deleted the folder /tmp/pytest-of-martin and ran the tox' test suite again.

Below you can see how much space it takes up.

➜  rm -rf /tmp/pytest-of-martin
## running tox
➜  du -h --max-depth=1 /tmp/pytest-of-martin | sort -h
2,1G	pytest-of-martin/pytest-1
3,5G	pytest-of-martin/pytest-2
5,8G	pytest-of-martin/pytest-0
12G	pytest-of-martin   

I'm not quite sure what is stored in there or what it is used for, but 12 GB seems quite extreme to me.

NB: I'm not sure if this is a bug, or desired behavior, but I thought it's worth reporting. 🙂

Environment

Provide at least:

• OS: Ubuntu 20.04

Output of pip list of the host Python, where tox is installed

Package               Version
--------------------- ----------------------
anyio                 4.3.0
argon2-cffi           23.1.0
argon2-cffi-bindings  21.2.0
attrs                 23.2.0
build                 1.2.1
cachetools            5.3.3
certifi               2024.2.2
cffi                  1.16.0
chardet               5.2.0
charset-normalizer    3.3.2
check-manifest        0.49
colorama              0.4.6
covdefaults           2.3.0
coverage              7.5.0
defusedxml            0.7.1
detect-test-pollution 1.2.0
devpi-client          7.0.3
devpi-common          4.0.4
devpi-process         1.0.0
devpi-server          6.11.0
diff_cover            9.0.0
distlib               0.3.8
execnet               2.1.1
filelock              3.13.4
flaky                 3.8.1
freezegun             1.5.0
h11                   0.14.0
hatch-vcs             0.4.0
hatchling             1.24.2
httpcore              1.0.5
httpx                 0.27.0
hupper                1.12.1
idna                  3.7
iniconfig             2.0.0
itsdangerous          2.2.0
Jinja2                3.1.3
lazy                  1.6
MarkupSafe            2.1.5
packaging             24.0
packaging-legacy      23.0.post0
passlib               1.7.4
PasteDeploy           3.1.0
pathspec              0.12.1
pip                   24.0
pkginfo               1.10.0
plaster               1.1.2
plaster-pastedeploy   1.0.1
platformdirs          4.2.1
pluggy                1.5.0
psutil                5.9.8
py                    1.11.0
pycparser             2.22
Pygments              2.17.2
pyproject-api         1.6.1
pyproject_hooks       1.0.0
pyramid               2.0.2
pytest                8.1.1
pytest-cov            5.0.0
pytest-mock           3.14.0
pytest-randomly       3.15.0
pytest-xdist          3.5.0
python-dateutil       2.9.0.post0
re-assert             1.1.0
regex                 2024.4.16
repoze.lru            0.7
requests              2.31.0
ruamel.yaml           0.18.6
ruamel.yaml.clib      0.2.8
setuptools            69.5.1
setuptools-scm        8.0.4
six                   1.16.0
sniffio               1.3.1
strictyaml            1.7.3
time-machine          2.14.1
toml                  0.10.2
tox                   4.14.3.dev17+g77564a1a
translationstring     1.4
trove-classifiers     2024.4.10
typing_extensions     4.11.0
urllib3               2.2.1
venusian              3.1.0
virtualenv            20.26.0
waitress              3.0.0
WebOb                 1.8.7
wheel                 0.43.0
zope.deprecation      5.0
zope.interface        6.3

Output of running tox

Output of tox -rvv

Minimal example

git clone https://github.com/tox-dev/tox.git
cd tox
pip install tox
tox

[RonnyPfannschmidt]

https://docs.pytest.org/en/8.1.x/reference/reference.html#confval-tmp_path_retention_policy may help to elevate that a little
alternatively, the test-suite would have to purge virtualenv's after successful use