gh-93353: regrtest creates worker directory in the parent

[vstinner]

regrtest now creates the working directory of the worker process in
the parent process.

Don't check for temporary files if Python is run on WASI: WASI
doesn't pass environment variables to the worker process.

[vstinner]

Tests / Address sanitizer (pull_request) Failing after 12m

Oh, there are many issues:

1 test altered the execution environment:
    test_threading

8 re-run tests:
    test_asyncio test_cmd_line_script test_compileall test_embed
    test_logging test_socket test_socketserver test_urllib

Many tests failed with "OSError: AF_UNIX path too long": I created issue #93852 for that.

test_compileall, test_cmd_line_script and test_urllib failed with UnicodeEncodeError:

======================================================================
ERROR: test_include_on_stdin (test.test_compileall.CommandLineTestsNoSourceEpoch.test_include_on_stdin)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/runner/work/cpython/cpython/Lib/test/test_py_compile.py", line 22, in wrapper
    return fxn(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^
  File "/home/runner/work/cpython/cpython/Lib/test/test_compileall.py", line 755, in test_include_on_stdin
    p.stdin.write((f3+os.linesep).encode('ascii'))
                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
UnicodeEncodeError: 'ascii' codec can't encode character '\xe6' in position 58: ordinal not in range(128)

======================================================================
ERROR: test_include_on_stdin (test.test_compileall.CommandLineTestsWithSourceEpoch.test_include_on_stdin)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/runner/work/cpython/cpython/Lib/test/test_py_compile.py", line 32, in wrapper
    return fxn(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^
  File "/home/runner/work/cpython/cpython/Lib/test/test_compileall.py", line 755, in test_include_on_stdin
    p.stdin.write((f3+os.linesep).encode('ascii'))
                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
UnicodeEncodeError: 'ascii' codec can't encode character '\xe6' in position 58: ordinal not in range(128)

======================================================================
ERROR: test_error (test.test_compileall.EncodingTest.test_error)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/runner/work/cpython/cpython/Lib/test/test_compileall.py", line 458, in test_error
    compileall.compile_dir(self.directory)
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/runner/work/cpython/cpython/Lib/compileall.py", line 116, in compile_dir
    for file in files:
    ^^^^^^^^^^^^^^^^^^
  File "/home/runner/work/cpython/cpython/Lib/compileall.py", line 29, in _walk_dir
    print('Listing {!r}...'.format(dir))
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
UnicodeEncodeError: 'ascii' codec can't encode character '\xe6' in position 67: ordinal not in range(128)

======================================================================
ERROR: test_file_notexists (test.test_urllib.urlopen_HttpTests.test_file_notexists)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/runner/work/cpython/cpython/Lib/urllib/parse.py", line 1004, in _to_bytes
    url = url.encode("ASCII").decode()
          ^^^^^^^^^^^^^^^^^^^
UnicodeEncodeError: 'ascii' codec can't encode character '\xe6' in position 75: ordinal not in range(128)

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/runner/work/cpython/cpython/Lib/test/test_urllib.py", line 535, in test_file_notexists
    with urlopen(tmp_fileurl) as fobj:
         ^^^^^^^^^^^^^^^^^^^^
  File "/home/runner/work/cpython/cpython/Lib/test/test_urllib.py", line 54, in urlopen
    return opener.open(url)
           ^^^^^^^^^^^^^^^^
  File "/home/runner/work/cpython/cpython/Lib/urllib/request.py", line 1760, in open
    fullurl = unwrap(_to_bytes(fullurl))
                     ^^^^^^^^^^^^^^^^^^
  File "/home/runner/work/cpython/cpython/Lib/urllib/parse.py", line 1006, in _to_bytes
    raise UnicodeError("URL " + repr(url) +
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
UnicodeError: URL 'file://localhost//home/runner/work/cpython/cpython/build/test_python_13115_æ/test_python_worker_61001_æ_tmpdir/tmpk_ljcax1' contains non-ASCII characters

======================================================================
ERROR: test_pep_409_verbiage (test.test_cmd_line_script.CmdLineTest.test_pep_409_verbiage)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/runner/work/cpython/cpython/Lib/test/test_cmd_line_script.py", line 551, in test_pep_409_verbiage
    text = stderr.decode('ascii').split('\n')
           ^^^^^^^^^^^^^^^^^^^^^^
UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 101: ordinal not in range(128)

======================================================================
ERROR: test_syntaxerror_indented_caret_position (test.test_cmd_line_script.CmdLineTest.test_syntaxerror_indented_caret_position)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/runner/work/cpython/cpython/Lib/test/test_cmd_line_script.py", line 616, in test_syntaxerror_indented_caret_position
    text = io.TextIOWrapper(io.BytesIO(stderr), 'ascii').read()
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/runner/work/cpython/cpython/Lib/encodings/ascii.py", line 26, in decode
    return codecs.ascii_decode(input, self.errors)[0]
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 66: ordinal not in range(128)

======================================================================
ERROR: test_syntaxerror_unindented_caret_position (test.test_cmd_line_script.CmdLineTest.test_syntaxerror_unindented_caret_position)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/runner/work/cpython/cpython/Lib/test/test_cmd_line_script.py", line 604, in test_syntaxerror_unindented_caret_position
    text = io.TextIOWrapper(io.BytesIO(stderr), 'ascii').read()
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/runner/work/cpython/cpython/Lib/encodings/ascii.py", line 26, in decode
    return codecs.ascii_decode(input, self.errors)[0]
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 66: ordinal not in range(128)

[vstinner]

test_embed failed with:

FAIL: test_init_pybuilddir (test.test_embed.InitConfigTests.test_init_pybuilddir)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/runner/work/cpython/cpython/Lib/test/test_embed.py", line 1345, in test_init_pybuilddir
    self.check_all_configs("test_init_compat_config", config,
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/runner/work/cpython/cpython/Lib/test/test_embed.py", line 790, in check_all_configs
    self.check_config(configs, expected_config)
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/runner/work/cpython/cpython/Lib/test/test_embed.py", line 716, in check_config
    self.assertEqual(config, expected)
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AssertionError: {'_co[351 chars]'], 'xoptions': [], 'warnoptions': [], 'python[1542 chars]': 0} != {'_co[351 chars]'], 'orig_argv': [], 'xoptions': [], 'warnopti[1691 chars]': 0}
  {'_config_init': 1,
   '_init_main': 1,
   '_install_importlib': 1,
   '_isolated_interpreter': 0,
   'argv': [''],
   'base_exec_prefix': '/usr/local',
   'base_executable': '/home/runner/work/cpython/cpython/build/test_python_13115_æ/test_python_worker_966257_æ_tmpdir/tmpa9n7bh3a/_testembed',
   'base_prefix': '/usr/local',
   'buffered_stdio': 1,
   'bytes_warning': 0,
   'check_hash_pycs_mode': 'default',
   'code_debug_ranges': 1,
   'configure_c_stdio': 0,
   'dev_mode': 0,
   'dump_refs': 0,
   'exec_prefix': '/usr/local',
   'executable': '/home/runner/work/cpython/cpython/build/test_python_13115_æ/test_python_worker_966257_æ_tmpdir/tmpa9n7bh3a/_testembed',
   'faulthandler': 0,
   'hash_seed': 0,
   'home': None,
   'import_time': 0,
   'inspect': 0,
   'install_signal_handlers': 1,
   'interactive': 0,
   'isolated': 0,
   'malloc_stats': 0,
   'module_search_paths': ['/usr/local/lib/python312.zip',
                           '/home/runner/work/cpython/cpython/Lib',
                           '/home/runner/work/cpython/cpython/build/lib.linux-x86_64-3.12',
                           '/usr/local/lib/python312.zip',
-                          '/home/runner/work/cpython/cpython/Lib',
+                          '/home/runner/work/cpython/cpython/build/test_python_13115_æ/test_python_worker_966257_æ_tmpdir/tmpa9n7bh3a/Lib',
                           '/home/runner/work/cpython/cpython/build/test_python_13115_æ/test_python_worker_966257_æ_tmpdir/tmpa9n7bh3a/libdir'],
   'module_search_paths_set': 1,
   'optimization_level': 0,
   'orig_argv': [],
   'parse_argv': 0,
   'parser_debug': 0,
   'pathconfig_warnings': 1,
   'platlibdir': 'lib',
   'prefix': '/usr/local',
   'program_name': './_testembed',
   'pycache_prefix': None,
   'pythonpath_env': '/usr/local/lib/python312.zip:/home/runner/work/cpython/cpython/Lib:/home/runner/work/cpython/cpython/build/lib.linux-x86_64-3.12',
   'quiet': 0,
   'run_command': None,
   'run_filename': None,
   'run_module': None,
   'safe_path': 0,
   'show_ref_count': 0,
   'site_import': 1,
   'skip_source_first_line': 0,
-  'stdlib_dir': '/home/runner/work/cpython/cpython/Lib',
+  'stdlib_dir': '/home/runner/work/cpython/cpython/build/test_python_13115_æ/test_python_worker_966257_æ_tmpdir/tmpa9n7bh3a/Lib',
   'tracemalloc': 0,
   'use_environment': 1,
-  'use_frozen_modules': 1,
?                        ^

+  'use_frozen_modules': True,
?                        ^^^^

   'use_hash_seed': 0,
   'user_site_directory': 1,
   'verbose': 0,
   'warn_default_encoding': 0,
   'warnoptions': [],
   'write_bytecode': 1,
   'xoptions': []}

[vstinner]

test_compileall, test_cmd_line_script and test_urllib failed with UnicodeEncodeError:

I reported issue #93855.

[vstinner]

I wrote PR #93909 which avoids issues #93852 and #93855.