Compiler resolve wrong implicit method when "-source 3.0-migration" is enabled

[SvenssonWeb]

Compiler version

Reproduced on 3.0.0 and 3.4.2

Suggest all versions in-between are affected.

Minimized code

object Bug {

  case class Wrapper[+E, +A](either: Either[E, A]) {
    def withFilter[EE >: E](p: A => Boolean)(implicit noE: A => EE): Wrapper[EE, A] = Wrapper(either match {
      case Right(a) => if (p(a)) Right(a) else Left(noE(a))
      case Left(e) => Left(e)
    })
  }

  def main(args: Array[String]): Unit = {

    val w1: Wrapper[String, Int] = Wrapper(Right(3))

    import scala.language.implicitConversions
    implicit def noE(i: Int): String = "No such element"

    val w4 = w1.withFilter(_ == 5)

    println((w4.either, Left(noE(1))))
    assert(w4.either == Left("No such element"))
  }
}

scala -source 3.0-migration Bug.scala

Output

(Left(3),Left(No such element))
Exception in thread "main" java.lang.AssertionError: assertion failed

Expectation

Should correctly execute the noE method as it should be passed via the implicit declaration in Wrapper.withFilter

(Left(No such element),Left(No such element))

[som-snytt]

It works again by defining

implicit def noE: Int => String = _ => "No such element"

Maybe it's the combination of inferring a union in Scala 3 plus not having a level test to prefer the local implicit to conforms.

(It works in Scala 2.)

[Gedochao]

As for the -source option, x.y-migration arguments are only supported as far as the oldest-still-supported LTS' minor version.
So in this case, we do not guarantee anything older than -source 3.3-migration would work.
And it does work for 3.3-migration.

This will not be worked on.