Fallback when SETUPTOOLS_USE_DISTUTILS=stdlib

Author: jaraco

setuptools/command/build_clib.py

@@ -1,7 +1,12 @@
 import distutils.command.build_clib as orig
 from distutils.errors import DistutilsSetupError
 from distutils import log
-from distutils._modified import newer_pairwise_group
+
+try:
+    from distutils._modified import newer_pairwise_group
+except ImportError:
+    # fallback for SETUPTOOLS_USE_DISTUTILS=stdlib
+    from .._distutils._modified import newer_pairwise_group
 
 
 class build_clib(orig.build_clib):