False positive warning for extension method (taking Seq) shadowing (varargs)

[eejbyfeldt]

Compiler version

3.7.3, 3.8.0-RC1-bin-20251017-96aff06-NIGHTLY

Minimized code

object test {
  class A {
    def m(p: String*): Unit = println("member")
  }
  extension (a: A) def m(p: Seq[String]): Unit = println("extension")

  def main(args: Array[String]): Unit = {
    (new A).m(Seq[String]())
  }
}

Output

$ scala-cli -S 3.nightly extension.scala 
Compiling project (Scala 3.8.0-RC1-bin-20251017-96aff06-NIGHTLY, JVM (21))
[warn] ./extension.scala:3:24
[warn] Extension method m will never be selected from type A
[warn] because A already has a member with the same name and compatible parameter types.
[warn]   extension (a: A) def m(p: Seq[String]): Unit = println("extension")
[warn]                        ^
Compiled project (Scala 3.8.0-RC1-bin-20251017-96aff06-NIGHTLY, JVM (21))
extension

Expectation

The compiler should not produce a warning. The warning is a false positive because the extension method is selected and called.