For transitions on label build settings, the value doesn't go through repo mapping

[Wyverald]

See https://github.com/Wyverald/bazel-label-transition-test

Basically, when defining a transition:

def _tr_impl(settings, attr):
  return {
    "@repo//:setting":  # goes through repo mapping
      "@repo//:target",  # does NOT go through repo mapping
  }

tr = transition(
  implementation = _tr_impl,
  inputs = [],
  outputs = ["@repo//:setting"],  # goes through repo mapping
)

[Wyverald]

cc @katre

[katre]

Thanks! How critical is this for your work? I see you've set this as a P2 already, is that accurate?

[Wyverald]

Ah don't worry, I'll try to fix this (as part of the greater effort to fix #14852). Just need to think about how, is all...

[katre]

SGTM, let me know if I can assist.