Some tests fail when __pycache__ prefix is set

[ringobanana-3900]

Bug report

Bug description:

Some tests that check .pyc files creation are failing when sys.pycache_prefix is set.

List of tests that failed on Arm64 MacOS (maybe there's more in skipped ones):

• test.test_inspect.test_inspect.TestModuleCLI.test_details_option_with_package
• test.test_import.PycacheTests.test_import_pyc_path
• test.test_import.PycacheTests.test_unwritable_directory
• test.test_importlib.test_util.PEP3147Tests.test_cache_from_source
• test.test_importlib.test_util.PEP3147Tests.test_cache_from_source_cwd
• test.test_importlib.test_util.PEP3147Tests.test_cache_from_source_no_dot
• test.test_importlib.test_util.PEP3147Tests.test_cache_from_source_optimization_None
• test.test_importlib.test_util.PEP3147Tests.test_cache_from_source_optimization_empty_string
• test.test_importlib.test_util.PEP3147Tests.test_cache_from_source_optimization_set
• test.test_importlib.test_util.PEP3147Tests.test_cache_from_source_path_like_arg
• test.test_py_compile.PyCompileCLITestCase.test_with_files
• test.test_py_compile.PyCompileTestsBase.test_double_dot_no_clobber
• test.test_compileall.CompileallTestsBase.test_include_on_stdin
• test.test_compileall.CompileallTestsBase.test_multiple_runs
• test.test_compileall.CompileallTestsBase.test_symlink_loop

example: PYTHONPYCACHEPREFIX="$HOME/__pycache__" ./python.exe -m test test.test_compileall test.test_import test.test_importlib.test_util test.test_inspect.test_inspect test.test_py_compile -v

output (edited for clarity and length): testres.txt

CPython versions tested on:

CPython main branch

Operating systems tested on:

macOS