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But if we don't make these changes, we should document them as limitations instead.

No chance to add some unit tests?

When I'm not sure about a PR, I like to get your overall opinion before I write unit tests

Also, I'm not sure that unit tests would help here. Probably better to add an integration test based on the reproducible examples.

@pditommaso I have trimmed this PR to focus on calling the onComplete on all error conditions, including the error function. Also added an e2e test

Notes:

• This PR calls all shutdown callbacks on abort, which includes the onComplete and the task monitor cleanup. This seems like a good thing? In fact I thought it was already doing this but I don't see any logic for it

• The onComplete is also allowed to call the error function, which could lead to the onComplete being called multiple times. It shouldn't cause an infinite recursion thanks to the existing error-handling logic in Session::abort() and other places. I think it's still fine to call error() in the onComplete, and as long as you do it in a sensible way, you will get sensible error messages