A task can run even if dependent tasks fail

[nh13]

I want to have a task that runs regardless of whether or not upstream tasks fail, just that they complete. For example, writing a final report, even if some metric tools fail, I still want it written. Perhaps something like =!=> means that it doesn't care about the successful completion of dependencies?

[tfenne]

I think there are two ways we could approach this - one would be to add a new kind of dependency. The other would be to add some sort of "on start" and "on stop" list to pipelines. The latter would make it easier to special case things, e.g. they could also be re-run on re-attempts of the pipeline. It would also make it easier to reason about cases like a ==> b ==> c =!=> d when, e.g., a fails.