`rose_prune` should prune on all platforms, not just the latest one

[MetRonnie]

rose_prune should prune on all platforms, not just one with the latest submit number. For example, a user might realise the original submission was to the wrong platform and broadcast and trigger on a new platform. I would expect rose_prune to clean up on both platforms not just the second one. However a fix for this will require PRs on both Rose and Cylc-Rose.

[cpelley]

This would be great and if I understand correctly, would remove the need for the HPC dummy tasks which run on different platforms to keep reference to relevant platforms in the current cycle for rose_prune.
rose_prune is configured with offset cycle housekeeping which means that it shouldn't be current cycle context only so running on all platforms would make better sense to me anyway.

[MetRonnie]

I think that is beyond the scope of this bugfix I'm afraid. It's been a couple of weeks since I looked at the code, but I think rose prune only looks at jobs in the specified cycle; the bugfix would stop it only looking at the latest submit number but it would still only look at the specified cycle.

[cpelley]

I think that is beyond the scope of this bugfix I'm afraid. It's been a couple of weeks since I looked at the code, but I think rose prune only looks at jobs in the specified cycle; the bugfix would stop it only looking at the latest submit number but it would still only look at the specified cycle.

Thanks @MetRonnie, that's a shame. I should prob. open an issue to discuss this elsewhere in that case 👍
Cheers