Use a centralized directory for files created by ctest

Defines a QGIS_TEST_TMP_DIR variable in top-level CMakeLists.txt
and then defines QGIS_CUSTOM_CONFIG_PATH and TMPDIR to be under
that directory for individual tests.

Closes qgisGH-50587
Closes qgisGH-48884

CMakeLists.txt

@@ -1192,6 +1192,8 @@ if (WITH_ASTYLE)
 endif()
 
 if (ENABLE_TESTS)
+  set(QGIS_TEST_TMP_DIR "${CMAKE_BINARY_DIR}/tmp")
+  message (STATUS "Ctest Temp Directory set to: ${QGIS_TEST_TMP_DIR}")
   add_subdirectory(tests)
   set (CTEST_BINARY_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/output/bin" )
   message (STATUS "Ctest Binary Directory set to: ${CTEST_BINARY_DIRECTORY}")

cmake/UsePythonTest.cmake

@@ -79,7 +79,7 @@ macro(ADD_PYTHON_TEST TESTNAME FILENAME)
 
   set_tests_properties(${TESTNAME} PROPERTIES
       FIXTURES_REQUIRED SOURCETREE
-      ENVIRONMENT "TMPDIR=${CMAKE_BINARY_DIR}/tmp"
+      ENVIRONMENT "TMPDIR=${QGIS_TEST_TMP_DIR};QGIS_CUSTOM_CONFIG_PATH=${QGIS_TEST_TMP_DIR}/config"
   )
 
 endmacro(ADD_PYTHON_TEST)

tests/src/CMakeLists.txt

@@ -26,10 +26,9 @@ if (ENABLE_TESTS)
       set_tests_properties(${TESTNAME} PROPERTIES LABELS ${ARG_QGIS_TEST_LABELS})
     endif()
 
-    # TODO: put the temp dir and custom config path under the build dir
     set_tests_properties(${TESTNAME} PROPERTIES
       FIXTURES_REQUIRED SOURCETREE
-      ENVIRONMENT "QGIS_CUSTOM_CONFIG_PATH=${CMAKE_BINARY_DIR}/tmp/qgis-tests/config"
+      ENVIRONMENT "TMPDIR=${QGIS_TEST_TMP_DIR};QGIS_CUSTOM_CONFIG_PATH=${QGIS_TEST_TMP_DIR}/config"
     )
 
     target_compile_definitions(${TESTNAME} PRIVATE "CMAKE_SOURCE_DIR=\"${CMAKE_SOURCE_DIR}\"")