Fixes test weirdness

celery/tests/tasks/test_tasks.py

@@ -128,6 +128,8 @@ class test_task_retries(TasksCase):
         self.retry_task_mockapply.push_request()
         try:
             with self.assertRaises(Retry):
+                import sys
+                sys.exc_clear()
                 self.retry_task_mockapply.retry(args=[4, 4], kwargs=None)
         finally:
             self.retry_task_mockapply.pop_request()