Create a fixture to patch-out compiler customization on macOS.

Author: jaraco

conftest.py

@@ -152,3 +152,10 @@ def temp_home(tmp_path, monkeypatch):
 def fake_home(fs, monkeypatch):
     home = fs.create_dir('/fakehome')
     return _set_home(monkeypatch, pathlib.Path(home.path))
+
+
+@pytest.fixture
+def disable_macos_customization(monkeypatch):
+    from distutils import sysconfig
+
+    monkeypatch.setattr(sysconfig, '_customize_macos', lambda: None)

distutils/tests/test_sysconfig.py

@@ -98,8 +98,6 @@ def set_executables(self, **kw):
             'CCSHARED': '--sc-ccshared',
             'LDSHARED': 'sc_ldshared',
             'SHLIB_SUFFIX': 'sc_shutil_suffix',
-            # On macOS, disable _osx_support.customize_compiler()
-            'CUSTOMIZED_OSX_COMPILER': 'True',
         }
 
         comp = compiler()
@@ -111,6 +109,7 @@ def set_executables(self, **kw):
         return comp
 
     @pytest.mark.skipif("get_default_compiler() != 'unix'")
+    @pytest.mark.usefixtures('disable_macos_customization')
     def test_customize_compiler(self):
         # Make sure that sysconfig._config_vars is initialized
         sysconfig.get_config_vars()