Comment by the_mitsuhiko | Hacker News Reader

Comment by the_mitsuhiko | Hacker News Reader

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Note how also in this stack trace you lose the information about where the main task was scheduled [1]. While you can stitch together the await points, it's much harder to find where tasks are originating. This is also true for `TaskGroup` where the actual call that schedules a task is lost. You will just find the eventual await, which might be the task group (which is good, since that would be structural concurrency), but often you just find nothing since it's not properly awaited or in a completely different place (eg: pending shutdown).

[1]: the important line is "main_task = loop.create_task(main())"

That's a good point. I would argue that both that line and the reported `loop.run_until_complete(main_task)` line are important, but then it becomes impossible to have a single linear trace when there are manually scheduled and waited on tasks mixed in.

At that point you have something like a "coroutine frame tree" instead of a "stack trace", where you potentially store multiple parent frames and source lines per coroutine frame. Could be presented something like:

  $ python3 test_stacktrace.py
  Traceback (most recent call last):
  * File "/home/user/tmp/test_stacktrace.py", line 22, in <module>
  |   main_task = loop.create_task(main())
  | * File "/home/user/tmp/test_stacktrace.py", line 24, in <module>
  |/    loop.run_until_complete(main_task)
  * File "/usr/lib/python3.10/asyncio/base_events.py", line 649, in run_until_complete
  |   return future.result()
  * File "/home/user/tmp/test_stacktrace.py", line 17, in main
  |   await foo()
  * File "/home/user/tmp/test_stacktrace.py", line 13, in foo
  |   await bar()
  * File "/home/user/tmp/test_stacktrace.py", line 9, in bar
  |   await baz()
  * File "/home/user/tmp/test_stacktrace.py", line 5, in baz
      raise RuntimeError()
  RuntimeError

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