diff -r 48fb6a4cb5f8 Lib/test/test_asyncio/test_tasks.py --- a/Lib/test/test_asyncio/test_tasks.py Mon Nov 28 11:45:58 2016 -0500 +++ b/Lib/test/test_asyncio/test_tasks.py Wed Nov 30 13:39:09 2016 -0500 @@ -1952,6 +1952,19 @@ self.assertFalse(gather_task.cancelled()) self.assertEqual(gather_task.result(), [42]) + def test_exception_traceback(self): + @asyncio.coroutine + def foo(): + 1 / 0 + + @asyncio.coroutine + def main(): + task = self.new_task(self.loop, foo()) + yield # skip one loop iteration + self.assertIsNotNone(task.exception().__traceback__) + + self.loop.run_until_complete(main()) + @mock.patch('asyncio.base_events.logger') def test_error_in_call_soon(self, m_log): def call_soon(callback, *args): diff -r 48fb6a4cb5f8 Modules/_asynciomodule.c --- a/Modules/_asynciomodule.c Mon Nov 28 11:45:58 2016 -0500 +++ b/Modules/_asynciomodule.c Wed Nov 30 13:39:09 2016 -0500 @@ -1042,6 +1042,8 @@ if (PyExceptionClass_Check(type)) { PyErr_NormalizeException(&type, &val, &tb); + /* No need to call PyException_SetTraceback since we'll be calling + PyErr_Restore for `type`, `val`, and `tb`. */ } else if (PyExceptionInstance_Check(type)) { if (val) { PyErr_SetString(PyExc_TypeError, @@ -2003,6 +2005,9 @@ if (!ev || !PyObject_TypeCheck(ev, (PyTypeObject *) et)) { PyErr_NormalizeException(&et, &ev, &tb); } + if (tb != NULL) { + PyException_SetTraceback(ev, tb); + } o = future_set_exception((FutureObj*)task, ev); if (!o) { /* An exception in Task.set_exception() */