Hi, I noticed that if a task in asyncio raises an exception, then the displayed traceback can be "polluted" by intermediate calls to task.result(). Also, the calls to task.result() can appear out of order relative to each other and to other lines. Here is an example: import asyncio async def raise_error(): raise ValueError() async def main(): task = asyncio.ensure_future(raise_error()) try: await task # call 1 except Exception: pass try: task.result() # call 2 except Exception: pass task.result() # call 3 asyncio.get_event_loop().run_until_complete(main()) The above outputs-- Traceback (most recent call last): File "test.py", line 24, in <module> asyncio.get_event_loop().run_until_complete(main()) File "/Users/.../3.6.4rc1/lib/python3.6/asyncio/base_events.py", line 467, in run_until_complete return future.result() File "test.py", line 21, in main task.result() # call 3 File "test.py", line 17, in main task.result() # call 2 File "test.py", line 12, in main await task # call 1 File "test.py", line 5, in raise_error raise ValueError() ValueError Notice that the "call 2" line appears in the traceback, even though it doesn't come into play in the exception. Also, the lines don't obey the "most recent call last" rule. If this rule were followed, it should be something more like-- Traceback (most recent call last): File "test.py", line 24, in <module> asyncio.get_event_loop().run_until_complete(main()) File "/Users/.../3.6.4rc1/lib/python3.6/asyncio/base_events.py", line 467, in run_until_complete return future.result() File "test.py", line 12, in main await task # call 1 File "test.py", line 5, in raise_error raise ValueError() File "test.py", line 17, in main task.result() # call 2 File "test.py", line 21, in main task.result() # call 3 ValueError If people agree there's an issue along these lines, I can file an issue in the tracker. I didn't seem to find one when searching for open issues with search terms like "asyncio traceback". Thanks, --Chris