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Hello,
I am running into an `asyncio` exception when using `DaskTaskRunner` which leads to tasks hanging and not completing. --&gt;

```13:44:03.390 | INFO    | Task run 'run_sofima-57be2d9c-1187' - Compute mesh for section test-experiment/Sample/s2098_g1.
13:44:07.972 | ERROR   | asyncio - Exception in callback WorkerThread._report_result(&lt;Future pendi...c62b6bc40&gt;()]&gt;, None, StopIteration())
handle: &lt;Handle WorkerThread._report_result(&lt;Future pendi...c62b6bc40&gt;()]&gt;, None, StopIteration())&gt;
Traceback (most recent call last):
  File "/tungstenfs/scratch/gmicro_share/_prefect/miniconda3/envs/test_gfriedri-em-alignment-flows/lib/python3.9/asyncio/events.py", line 80, in _run
    self._context.run(self._callback, *self._args)
  File "/tungstenfs/scratch/gmicro_share/_prefect/miniconda3/envs/test_gfriedri-em-alignment-flows/lib/python3.9/site-packages/anyio/_backends/_asyncio.py", line 849, in _report_result
    future.set_exception(exc)
TypeError: StopIteration interacts badly with generators and cannot be raised into a Future```

The worker then continues to complete other tasks submitted to it. But this failed tasks stays pending indefinitely which blocks the whole flow eventually.

Probably related to this: <https://github.com/agronholm/anyio/pull/477>

I agree with your assessment that it is related to the error you posted. It looks like <https://github.com/tiangolo/fastapi/issues/966#issuecomment-1305615341|it may be fixed> in a future version of AnyIO (ver 4.0.0).

For now I am catching the `StopIteration` exception inside the task and raise a `RunTime`  exception. Not sure if it makes sense to add this "fix" to the prefect task until AnyIO 4.0 is released.

<@U033ZL050FR> Can you help me understand this solution a little better? I'm wrapping the call to the function where it dies in `try/except` and it's still dying on me

This is happening with a relatively straight-forward SequentialTaskRunner:
```19:17:21.709 | ERROR   | asyncio - Exception in callback WorkerThread._report_result(&lt;Future pendi...0fdcc64c0&gt;()]&gt;, None, StopIteration())
handle: &lt;Handle WorkerThread._report_result(&lt;Future pendi...0fdcc64c0&gt;()]&gt;, None, StopIteration())&gt;                                                                                                                                           
Traceback (most recent call last):
  File "/usr/lib/python3.8/asyncio/events.py", line 81, in _run
    self._context.run(self._callback, *self._args)
  File "/big/.virtualenvs/kate_tooling/lib/python3.8/site-packages/anyio/_backends/_asyncio.py", line 849, in _report_result
    future.set_exception(exc)
TypeError: StopIteration interacts badly with generators and cannot be raised into a Future   ```

This is where I am wrapping the function call: <https://github.com/fmi-basel/gfriedri-em-alignment-flows/blob/94d8332470e248f54b7c20d21e4b151803f748bc/flows/sofima_tasks/sofima_tasks.py#L48>
And here I call the task inside the flow: <https://github.com/fmi-basel/gfriedri-em-alignment-flows/blob/94d8332470e248f54b7c20d21e4b151803f748bc/flows/tile_registration.py#L184>
I am using `DaskTaskRunner` and `map`.

This "fix" will only fix the issue I had with flows staying in a running state forever. It turns the flow into a failed state due to the raised `RunTimeException`.

PS: Please don´t judge the code quality. This repo is still under heavy construction in at least 5 places.