It would be awesome 
to be able to retry a triggered build in a parent pipeline. Currently retrying the build via the retry button on the triggered build page, creates a new build that is not linked to the original parent build. It would be great to be able to retry the triggered pipeline and have the retried build be linked to the original top level’s pipeline passing status.
I think this would save me quite a bit of build time, and simplify understanding how to retry downstream builds too.
We often trigger quite lengthy sub-builds, and while we aim to make them internally retry-able, sometimes we can’t quite get there, or things fail in interesting ways (e.g. the one I just ran into: in a triggered build, a “successful” (but not really) step emitted a corrupted artifact to a downstream step, which failed, but the original step wouldn’t allow retry on success)
In such cases, being able to “retrigger” a downstream build is very useful.