Merge pull request #2907 from pypa/bugfix/2906-distutils-race

In ensure_local_distutils, re-use DistutilsMetaFinder

_distutils_hack/__init__.py

@@ -48,11 +48,15 @@ def enabled():
 
 def ensure_local_distutils():
     clear_distutils()
-    distutils = importlib.import_module('setuptools._distutils')
-    distutils.__name__ = 'distutils'
-    sys.modules['distutils'] = distutils
 
-    # sanity check that submodules load as expected
+    # With the DistutilsMetaFinder in place,
+    # perform an import to cause distutils to be
+    # loaded from setuptools._distutils. Ref #2906.
+    add_shim()
+    importlib.import_module('distutils')
+    remove_shim()
+
+    # check that submodules load as expected
     core = importlib.import_module('distutils.core')
     assert '_distutils' in core.__file__, core.__file__
 

changelog.d/2906.misc.rst

@@ -0,0 +1 @@
+In ensure_local_distutils, re-use DistutilsMetaFinder to load the module. Avoids race conditions when _distutils_system_mod is employed.

setuptools/tests/test_test.py

@@ -1,5 +1,3 @@
-from distutils import log
-
 import pytest
 from jaraco import path
 
@@ -9,14 +7,7 @@
 from .textwrap import DALS
 
 
-@pytest.fixture
-def quiet_log():
-    # Running some of the other tests will automatically
-    # change the log level to info, messing our output.
-    log.set_verbosity(0)
-
-
-@pytest.mark.usefixtures('tmpdir_cwd', 'quiet_log')
+@pytest.mark.usefixtures('tmpdir_cwd')
 def test_tests_are_run_once(capfd):
     params = dict(
         name='foo',
@@ -46,4 +37,5 @@ def test_test(self):
     cmd.ensure_finalized()
     cmd.run()
     out, err = capfd.readouterr()
-    assert out == 'Foo\n'
+    assert out.endswith('Foo\n')
+    assert len(out.split('Foo')) == 2