Document that usage of _config_vars is very purposeful Closes #4228

+ try to resolve doc issue

Author: Avasam

docs/conf.py

@@ -168,16 +168,17 @@
     ('py:attr', 'CCompiler.language_map'),  # undocumented
     ('py:attr', 'CCompiler.language_order'),  # undocumented
     ('py:class', 'distutils.dist.Distribution'),  # undocumented
+    ('py:class', 'distutils.dist.DistributionMetadata'),  # undocumented
     ('py:class', 'distutils.extension.Extension'),  # undocumented
     ('py:class', 'BorlandCCompiler'),  # undocumented
     ('py:class', 'CCompiler'),  # undocumented
     ('py:class', 'CygwinCCompiler'),  # undocumented
-    ('py:class', 'distutils.dist.DistributionMetadata'),  # undocumented
     ('py:class', 'FileList'),  # undocumented
     ('py:class', 'IShellLink'),  # ref to MS docs
     ('py:class', 'MSVCCompiler'),  # undocumented
     ('py:class', 'OptionDummy'),  # undocumented
     ('py:class', 'UnixCCompiler'),  # undocumented
+    ('py:class', 'setuptools.dist.Distribution'),  # undocumented
     ('py:exc', 'CompileError'),  # undocumented
     ('py:exc', 'DistutilsExecError'),  # undocumented
     ('py:exc', 'DistutilsFileError'),  # undocumented

setuptools/command/build_ext.py

@@ -26,7 +26,9 @@
 
 # make sure _config_vars is initialized
 get_config_var("LDSHARED")
-from distutils.sysconfig import _config_vars as _CONFIG_VARS  # type: ignore # noqa # Not publicly exposed in typeshed distutils stubs
+# Not publicly exposed in typeshed distutils stubs, but this is done on purpose
+# See https://github.com/pypa/setuptools/pull/4228#issuecomment-1959856400
+from distutils.sysconfig import _config_vars as _CONFIG_VARS  # type: ignore # noqa
 
 
 def _customize_compiler_for_shlib(compiler):