Is it possible to retry mapped tasks? Whenever I try it I get nulls being passed as the mapped input parameter. We are using prefect cloud with prefect results.

Hey @Trevor Kramer, are you using caching by chance?

I am not using result templates - I didn't think that was necessary with PrefectResults

I don’t think it is. I was just wondering if there was already a result seen and the mapped task is skipping cuz of it. I misunderstood. It sounds like the issue is when you restart it doesn’t know the values anymore. Let me look a bit.

we set flow.result = PrefectResult() before we register

Ok so I will look more into this tomorrow when the team is around to give you a better answer but at the moment I suspect that this is not working because

flow.result = PrefectResult()

is applied to all tasks as a place to write results, but I think it gets overwritten with each task. If there is a mapped task, I think only one value is saved at a time. When you try to retry from failure, there is only one thing to pull at most for the mapped task (assuming the parameter came from the preceding task).

I think the issue is that flow.result doesn't seem to be respected. If I set

Flow('pipeline', result=PrefectResult())

then it works as expected.

Oh that’s good to know. Thanks for circling back on this! I will explore this and we’ll see if we need to open an issue for this on our end.