false `unused import` warning for scala.compiletime.deferred

[OlgaDor]

Compiler version

Scala 3.6.2 with scalacOptions "-Wunused:imports"

Minimized code

import scala.compiletime.deferred

class Context

trait Foo:
  given context: Context = deferred

Output

Scala compiler returns a warning
unused import import scala.compiletime.deferred

The incorrect warning results in misleading highlighting in IntelliJ IDEA when compiler-based highlighting is enabled

Expectation

The compiler should not return an "unused import" warning for scala.compiletime.deferred, as it is clearly used in the code

[som-snytt]

See #21805 which is an umbrella ticket for compiletime.

I'll work my way through the use cases, but I just pushed this one, thanks. In this case, I think it will not support name fidelity, e.g.,

import compiletime.deferred as dufuhhed

Edit: actually the warning would take the highest precedence import in any case.

But TIL:

   |Note that `deferred` can only be used under its own name when implementing a given in a trait; `defuhhed` is not accepted.