capture stderr to silence output during test_coroutines (closes #27968)

benjaminp · benjaminp · commit 48c88307d87a · 2016-09-07T09:00:48.000-07:00
diff --git a/Lib/test/test_coroutines.py b/Lib/test/test_coroutines.py
@@ -1568,10 +1568,11 @@ async def func(): pass
     def test_fatal_coro_warning(self):
         # Issue 27811
         async def func(): pass
-        with warnings.catch_warnings():
+        with warnings.catch_warnings(), support.captured_stderr() as stderr:
             warnings.filterwarnings("error")
             func()
             support.gc_collect()
+        self.assertIn("was never awaited", stderr.getvalue())
 
 
 class CoroAsyncIOCompatTest(unittest.TestCase):
