Building rust nightly requires rustBeta.
Both of which take 1.5 hours to compile.
This includes them into hydra builds so we don't waste peoples time too much.
@globin From what i can tell at the #18101 discussion, i should probably add lowPrio to rustBeta and rustNightly, no?
That way we get hydra builds and the right priorities.
@exi yes, right
updated to use lowPrio
rust: make rust beta and nightly be build by hydra