CI tests failing

[jaraco]

Last night, I was applying some changes from jaraco/skeleton, including a fix for breakage in tox 4 (jaraco/skeleton#74). Merging the skeleton introduces other changes, such as testing on Python 3.12. Regardless, after merging the skeleton, there are still some new test failures.

[jaraco]

I see now the issue. In the new matrix, for some jobs, SETUPTOOLS_USE_DISTUTILS is set to , but a lot of the logic depends on the value being set to either "local" or "stdlib". In particular, the detection behavior treats blank as "stdlib":

setuptools/_distutils_hack/__init__.py

Lines 47 to 48 in e12f73c

	which = os.environ.get('SETUPTOOLS_USE_DISTUTILS', 'local')
	return which == 'local'

But the workaround for distutils detection in test_manifest treats blank as "local":

setuptools/setuptools/tests/test_manifest.py

Lines 327 to 335 in e12f73c

	@pytest.fixture(autouse=os.getenv("SETUPTOOLS_USE_DISTUTILS") == "stdlib")
	def _compat_record_logs(self, monkeypatch, caplog):
	"""Account for stdlib compatibility"""
	def _log(_logger, level, msg, args):
	exc = sys.exc_info()
	rec = logging.LogRecord("distutils", level, "", 0, msg, args, exc)
	caplog.records.append(rec)
	monkeypatch.setattr(log.Log, "_log", _log)

So the tests are running as stdlib, when we really want these tests to run as "local".

[jaraco]

I plan to take this opportunity to treat a blank value as not supplied (same as 'local') in _distutils_hack.

[jaraco]

While troubleshooting this issue, I noticed that pypy tests fail to install if SETUPTOOLS_USE_DISTUTILS=local. That's weird and surprising and concerning.