Directory /tmp full of QGIS temporary files after ctest run

[strk]

What is the bug or the crash?

The /tmp/ directory is filled with temporary files created by QGIS testsuite and not cleaned up on completion.
This is a partial list:

dot-qgis
oauth2-cache
QGIS-TEST-gAWuVQ
QGIS-TEST.RnZLfj
srs6.db

It would help if at least those files were in a SINGLE directory. Maybe it can be done with a fixture creating such temporary dir..

Steps to reproduce the issue

Run any test, for example:

xvfb-run ctest --output-on-failure -R gui_datumtransform

Check the /tmp directory before and after that run

Versions

Current master as of 6 June 2022, aka ac7b711

Supported QGIS version

• I'm running a supported QGIS version according to the roadmap.

New profile

• I tried with a new QGIS profile

Additional context

No response

[strk]

This is still an issue, which prevents me from running the testsuite w/out filling up my disk.

[strk]

As reported in #50415 there's something deep in core that triggers proliferation of files too.

See what happens when running a SINGLE qgis test:

while :; do TMPDIR=/tmp/qgis ctest -R ^PyQgsServerLocaleOverride > /dev/null && du -s /tmp/qgis; done
16028   /tmp/qgis
17156   /tmp/qgis
18284   /tmp/qgis
19412   /tmp/qgis

That's over 1kb growth on every run of that specific test (it was just a random one).

[strk]

The python start_app() method defined in package qgis.testing is responsible on itself for the creation of 3 directories, one of which full of things. Example data created (and not removed) by running an empty python test only calling start_app():

/tmp/qgis_tests/QGIS-PythonTestConfigPathj8vne5tm
/tmp/qgis_tests/QGIS-PythonTestConfigPathj8vne5tm/profiles
/tmp/qgis_tests/QGIS-PythonTestConfigPathj8vne5tm/profiles/default
/tmp/qgis_tests/QGIS-PythonTestConfigPathj8vne5tm/profiles/default/Unknown Organization
/tmp/qgis_tests/QGIS-PythonTestConfigPathj8vne5tm/profiles/default/Unknown Organization/test_qgsfields.py.ini
/tmp/qgis_tests/QGIS-PythonTestConfigPathj8vne5tm/profiles/default/qgis.db
/tmp/qgis_tests/QGIS-PythonTestConfigPathj8vne5tm/profiles/default/fonts
/tmp/qgis_tests/QGIS-PythonTestConfigPathj8vne5tm/profiles/default/bookmarks.xml
/tmp/qgis_tests/QGIS-PythonTestConfigPathj8vne5tm/profiles/default/symbology-style.db
/tmp/qgis_tests/QGIS-PythonTestConfigPathj8vne5tm/profiles/default/qgis-auth.db
/tmp/qgis_tests/QGIS-PythonTestConfigPathj8vne5tm/profiles/default/palettes
/tmp/qgis_tests/QGIS-PythonTestConfigPathj8vne5tm/profiles/default/oauth2-cache
/tmp/qgis_tests/test_qgsfields.py-vdyVNh
/tmp/qgis_tests/test_qgsfields.py-cBMsGe

Everything is under /tmp/qgis_tests because I've exported TMPDIR=/tmp/qgis_tests to simplify cleaning up all those files, which I think should be cleaned up automatically upon process end instead.

[strk]

The temporary python test config path cleanup is implemented in PR #50608

[strk]

Re-opened by revert, will be closed again by merging GH-57934