First applicable import is marked used when ambiguity is resolved

[som-snytt]

//> using scala 2.13.15
//> using options -Wunused:imports -Xsource:3

import Dog.Owner

class Dog(owner: Owner) {
  import Dog.*

  val getOwner: Owner = owner
}

object Dog {
  class Owner
}

Problem

Unlike future dotty, there is no warning for the inner import, most likely because the compiler picks it after reconciling with the outer import. It would be equally valid to pick the higher-precedence binding.

Conversely, it's desirable perhaps to "use" the import of smallest scope and report the other unused if possible. That is, this is where separate analysis shines: the compiler behavior per se doesn't matter for "minimizing" imports.

If the outer import were also wildcard, and so, equal precedence, it's also preferable to warn about the inner import. For simplicity, pick the highest precedence, outermost import as "canonical form".

The example is due to scala/scala3#21917