Make stdlib distutils the default again. Stop the burning. Ref #2350 and others.

_distutils_hack/__init__.py

@@ -37,7 +37,7 @@ def enabled():
     """
     Allow selection of distutils by environment variable.
     """
-    which = os.environ.get('SETUPTOOLS_USE_DISTUTILS', 'local')
+    which = os.environ.get('SETUPTOOLS_USE_DISTUTILS', 'stdlib')
     return which == 'local'
 
 

changelog.d/2350.change.rst

+Setuptools reverts using the included distutils by default. Platform maintainers and system integrators and others are *strongly* encouraged to set ``SETUPTOOLS_USE_DISTUTILS=local`` to help identify and work through the reported issues with distutils adoption, mainly to file issues and pull requests with pypa/distutils such that distutils performs as needed across every supported environment.

setup.py

@@ -100,7 +100,7 @@ class install_with_pth(install):
     _pth_contents = textwrap.dedent("""
         import os
         var = 'SETUPTOOLS_USE_DISTUTILS'
-        enabled = os.environ.get(var, 'local') == 'local'
+        enabled = os.environ.get(var, 'stdlib') == 'local'
         enabled and __import__('_distutils_hack').add_shim()
         """).lstrip().replace('\n', '; ')