From 9c9c91c0a3951a7c521bd6eddc3aa5f84f0cfd9f Mon Sep 17 00:00:00 2001
From: "Jason R. Coombs" <jaraco@jaraco.com>
Date: Tue, 28 Dec 2021 14:34:37 -0500
Subject: [PATCH] Bypass distutils loader when setuptools module is no longer
 available on sys.path. Fixes #2980.

---
 _distutils_hack/__init__.py | 7 +++++++
 changelog.d/2980.misc.rst   | 1 +
 2 files changed, 8 insertions(+)
 create mode 100644 changelog.d/2980.misc.rst

diff --git a/_distutils_hack/__init__.py b/_distutils_hack/__init__.py
index 85a51370b6..55ea082565 100644
--- a/_distutils_hack/__init__.py
+++ b/_distutils_hack/__init__.py
@@ -86,6 +86,13 @@ def spec_for_distutils(self):
         import importlib.abc
         import importlib.util
 
+        # In cases of path manipulation during sitecustomize,
+        # Setuptools might actually not be present even though
+        # the hook has been loaded. Allow the caller to fall
+        # back to stdlib behavior. See #2980.
+        if not importlib.util.find_spec('setuptools'):
+            return
+
         class DistutilsLoader(importlib.abc.Loader):
 
             def create_module(self, spec):
diff --git a/changelog.d/2980.misc.rst b/changelog.d/2980.misc.rst
new file mode 100644
index 0000000000..222a3adbf2
--- /dev/null
+++ b/changelog.d/2980.misc.rst
@@ -0,0 +1 @@
+Bypass distutils loader when setuptools module is no longer available on sys.path.