Suppress distutils replacement when building or testing CPython. Fixes #2965. Fixes #3007.

1 files changed, 11 insertions, 0 deletions

diff --git a/_distutils_hack/__init__.py b/_distutils_hack/__init__.py
index 399d22f1..1f8daf49 100644
--- a/_distutils_hack/__init__.py
+++ b/_distutils_hack/__init__.py
@@ -89,6 +89,9 @@ class DistutilsMetaFinder:
         return method()
 
     def spec_for_distutils(self):
+        if self.is_cpython():
+            return
+
         import importlib
         import importlib.abc
         import importlib.util
@@ -118,6 +121,14 @@ class DistutilsMetaFinder:
             'distutils', DistutilsLoader(), origin=mod.__file__
         )
 
+    @staticmethod
+    def is_cpython():
+        """
+        Suppress supplying distutils for CPython (build and tests).
+        Ref #2965 and #3007.
+        """
+        return os.path.isfile('pybuilddir.txt')
+
     def spec_for_pip(self):
         """
         Ensure stdlib distutils when running under pip.