Add debug statements for visibility

Author: abravalheri

setuptools/version.py

@@ -1,6 +1,6 @@
 from ._importlib import metadata
 
 try:
-    __version__ = metadata.version('setuptools')
+    __version__ = metadata.version('setuptools') or 'unknown'
 except Exception:
     __version__ = 'unknown'

tox.ini

@@ -12,6 +12,8 @@ setenv =
 	PYTHONWARNDEFAULTENCODING = 1
 	SETUPTOOLS_ENFORCE_DEPRECATION = 1
 commands =
+	python -c 'from pathlib import Path; p = Path("setuptools.egg-info/PKG-INFO"); print(p.read_text(encoding="utf-8") if p.exists() else "NO PKG-INFO")'  # DEBUG
+	# ^ ensure no malformed egg-info in flaky tests
 	pytest {posargs}
 usedevelop = True
 extras =