Add requires_subinterpreters decorator

Author: hoodmane

Lib/test/test_capi/test_misc.py

@@ -2137,6 +2137,7 @@ def test_py_config_isoloated_per_interpreter(self):
         # test fails, assume that the environment in this process may
         # be altered and suspect.
 
+    @requires_subinterpreters
     @unittest.skipUnless(hasattr(os, "pipe"), "requires os.pipe()")
     def test_configured_settings(self):
         """
@@ -2215,17 +2216,16 @@ def test_configured_settings(self):
                 self.assertEqual(settings, expected)
 
         # expected to fail
-        if _interpreters is not None:
-            for config in expected_to_fail:
-                kwargs = dict(zip(kwlist, config))
-                with self.subTest(config):
-                    script = textwrap.dedent(f'''
-                        import _testinternalcapi
-                        _testinternalcapi.get_interp_settings()
-                        raise NotImplementedError('unreachable')
-                        ''')
-                    with self.assertRaises(_interpreters.InterpreterError):
-                        support.run_in_subinterp_with_config(script, **kwargs)
+        for config in expected_to_fail:
+            kwargs = dict(zip(kwlist, config))
+            with self.subTest(config):
+                script = textwrap.dedent(f'''
+                    import _testinternalcapi
+                    _testinternalcapi.get_interp_settings()
+                    raise NotImplementedError('unreachable')
+                    ''')
+                with self.assertRaises(_interpreters.InterpreterError):
+                    support.run_in_subinterp_with_config(script, **kwargs)
 
     @unittest.skipIf(_testsinglephase is None, "test requires _testsinglephase module")
     @unittest.skipUnless(hasattr(os, "pipe"), "requires os.pipe()")