BUG: Make sdist use distutils.

If sdist uses setuptools there can be problems, see gh-7127.

1 files changed, 8 insertions, 5 deletions

diff --git a/setup.py b/setup.py
index 4335e417a..5e8290a7a 100755
--- a/setup.py
+++ b/setup.py
@@ -60,8 +60,10 @@ if os.path.exists('MANIFEST'):
     os.remove('MANIFEST')
 
 # We need to import setuptools here in order for it to persist in sys.modules.
-# Its presence/absence is used in subclassing setup in numpy/distutils/core.py,
-# which may not be the most robust design.
+# Its presence/absence is used in subclassing setup in numpy/distutils/core.py.
+# However, we need to run the distutils version of sdist, so import that first
+# so that it is in sys.modules
+import numpy.distutils.command.sdist
 import setuptools
 
 # Initialize cmdclass from versioneer
@@ -158,13 +160,14 @@ class concat_license_files():
             f.write(self.bsd_text)
 
 
-sdist_class = cmdclass['sdist']
-class sdist_checked(sdist_class):
+# Need to inherit from versioneer version of sdist to get the encoded
+# version information.
+class sdist_checked(cmdclass['sdist']):
     """ check submodules on sdist to prevent incomplete tarballs """
     def run(self):
         check_submodules()
         with concat_license_files():
-            sdist_class.run(self)
+            super().run()
 
 
 def get_build_overrides():