`-Wunused:locals` gives false positives for structural types in local scopes

[matil019]

Compiler version

3.3.0

Minimized code

//> using scala "3.3.0"
//> using options "-Wunused:locals"

class Record(elems: (String, Any)*) extends Selectable:
  private val fields = elems.toMap
  def selectDynamic(name: String): Any = fields(name)

type Person = Record { val name: String; val age: Int }

object Main {
  locally {
    def good: Person = ???
    def bad1: Record { val name: String; val age: Int } = ???
    def bad2 = (good: Record { val name: String; val age: Int })
    (bad1, bad2)
  }
}

Compile it with:

scalac -Wunused:locals Main.scala

Output

-- Warning: Main.scala:10:27 ---------------------------------------------------
10 |    def bad1: Record { val name: String; val age: Int } = ???
   |                           ^^^^
   |                           unused local definition
-- Warning: Main.scala:10:45 ---------------------------------------------------
10 |    def bad1: Record { val name: String; val age: Int } = ???
   |                                             ^^^
   |                                             unused local definition
-- Warning: Main.scala:11:35 ---------------------------------------------------
11 |    def bad2 = (good: Record { val name: String; val age: Int })
   |                                   ^^^^
   |                                   unused local definition
-- Warning: Main.scala:11:53 ---------------------------------------------------
11 |    def bad2 = (good: Record { val name: String; val age: Int })
   |                                                     ^^^
   |                                                 unused local definition
4 warnings found

Expectation

No warnings are issued.

Note that removing the locally block and putting the definitions directly into Main suppresses the warnings, presumably because they are no longer local.

[bishabosha]

for comparison the following compiles in Scala 2.13.10 with no warnings, as expected:

//> using option -Wunused:locals
//> using scala 2.13

package foo {
  class Record(elems: (String, Any)*) {
    private val fields = elems.toMap
    def selectDynamic(name: String): Any = fields(name)
  }

  object Main {
    locally {
      def good: Person = ???
      def bad1: Record { val name: String; val age: Int } = ???
      def bad2 = (good: Record { val name: String; val age: Int })
      (bad1, bad2)
    }
  }

}

package object foo {
  type Person = Record { val name: String; val age: Int }
}

[bishabosha]

@KacperFKorban feel free to reassign, I saw you have worked on these warnings previously