Reduce pollution of system directories during test runs

[strk]

Closes GH-57610
Closes GH-50587
Closes GH-48884

[github-actions]

🪟 Windows builds ready!

Windows builds of this PR are available for testing here. Debug symbols for this build are available here.

(Built from commit 605cafc)

[strk]

CI reported failure is:

FAIL!  : TestQgsProject::testAsynchronousLayerLoading() Compared values are not the same
   Actual   (project->mapLayers( true ).count()): 0
   Expected (layersCount - 2)                   : 57
   Loc: [/root/QGIS/tests/src/core/testqgsproject.cpp(1098)]

https://github.com/qgis/QGIS/actions/runs/9284356490/job/25547985232?pr=57606#step:13:905

[strk]

For the record: this is the count of files found in the tmp/ directory after make check:

$ find tmp/ -type f | wc -l
3916

All those will now at least be under a single directory, to make their removal easier (with this PR)

[strk]

The failure in this PR is due to a bug in a test which is fixed by GH-57612 -- once that is merged this can be rebased

[lnicola]

Hey @strk, this looks like a pretty trivial PR, but nobody seems to be available to merge it.

But it doesn't look obviously wrong to me. Do you want me to file an identical PR that you could approve, working around the slow review times? It would mean bypassing the merge rules, but if nobody complains maybe that's fine.

[nyalldawson]

@strk I need to revert this -- it's broken my build and causes running tests from a non-installed build to segfault.

[strk]

@nyalldawson could you file a separate ticket and add a stacktrace ? A segfault upon specifying a custom tmpdir is most likely a missing check in a testcase

[nyalldawson]

@strk

nyall@nyall-framework:~/dev/build-qgis$ ctest -R GdalProvider\$ -V
UpdateCTestConfiguration  from :/home/nyall/dev/build-qgis/DartConfiguration.tcl
Parse Config file:/home/nyall/dev/build-qgis/DartConfiguration.tcl
 Add coverage exclude regular expressions.
 Add coverage exclude: /CMakeFiles/CMakeTmp/
UpdateCTestConfiguration  from :/home/nyall/dev/build-qgis/DartConfiguration.tcl
Parse Config file:/home/nyall/dev/build-qgis/DartConfiguration.tcl
Test project /home/nyall/dev/build-qgis
Constructing a list of tests
Done constructing a list of tests
Updating test list for fixtures
Added setup test logGitStatus required by fixture SOURCETREE
Added cleanup test checkGitStatus required by fixture SOURCETREE
Added 2 tests to meet fixture requirements
Checking test dependency graph...
Checking test dependency graph end
test 1
    Start   1: logGitStatus

1: Test command: /home/nyall/dev/QGIS/scripts/chkgitstatus.sh "log"
1: Working Directory: /home/nyall/dev/build-qgis
1: Test timeout computed to be: 1500
1/3 Test   #1: logGitStatus .....................   Passed    0.05 sec
test 496
    Start 496: PyQgsGdalProvider

496: Test command: /usr/bin/cmake "-P" "/home/nyall/dev/build-qgis/tests/src/python/PyQgsGdalProvider.cmake"
496: Working Directory: /home/nyall/dev/build-qgis/tests/src/python
496: Environment variables: 
496:  TMPDIR=/home/nyall/dev/build-qgis/tmp
496:  QGIS_CUSTOM_CONFIG_PATH=/home/nyall/dev/build-qgis/tmp/config
496: Test timeout computed to be: 1500
496: export =
496: export PYTHONPATH=/home/nyall/dev/build-qgis/output/python:/home/nyall/dev/build-qgis/output/python/plugins:/home/nyall/dev/QGIS/tests/src/python:
496: -- Running  /usr/bin/python3.12 /home/nyall/dev/QGIS/tests/src/python/test_provider_gdal.py
496: src/core/providers/qgsproviderregistry.cpp:372 : (init) [339ms] Loaded 33 providers (OAPIF;WFS;arcgisfeatureserver;arcgismapserver;arcgisvectortileservice;cesiumtiles;copc;delimitedtext;ept;gdal;gpx;grass;grassraster;mbtilesvectortiles;mdal;memory;mesh_memory;mssql;ogr;pdal;postgres;postgresraster;sensorthings;spatialite;tiledscene;vectortile;virtual;virtualraster;vpc;vtpkvectortiles;wcs;wms;xyzvectortiles) 
496: QFile::remove: Empty or null file name
496: /usr/lib64/python3.12/site-packages/osgeo/gdal.py:312: FutureWarning: Neither gdal.UseExceptions() nor gdal.DontUseExceptions() has been explicitly called. In GDAL 4.0, exceptions will be enabled by default.
496:   warnings.warn(
496: GDAL ERROR 1: Unable to compute a transformation between pixel/line and georeferenced coordinates for testInt8.tif. There is no affine transformation and no GCPs. Specify transformation option SRC_METHOD=NO_GEOTRANSFORM to bypass this check.
496: GDAL ERROR 1: Unable to compute a transformation between pixel/line and georeferenced coordinates for testInt8.tif. There is no affine transformation and no GCPs. Specify transformation option SRC_METHOD=NO_GEOTRANSFORM to bypass this check.
496: .....src/core/qgsmessagelog.cpp:39 : (logMessage) [121ms] 2024-06-27T12:57:07 WCS[1] Download of capabilities failed: Protocol "" is unknown
496: src/core/qgsmessagelog.cpp:39 : (logMessage) [0ms] 2024-06-27T12:57:07 WCS[1] Download of capabilities failed: Protocol "" is unknown
496: src/providers/wcs/qgswcscapabilities.cpp:326 : (describeCoverage) [0ms] coverage not found
496: .Could not create temporary copy
496: CMake Error at PyQgsGdalProvider.cmake:23 (message):
496:   Test failed: Subprocess aborted