Cannot use modify in opaque types

[OndrejSpanel]

Following opaque type has defined both getters and copy, but it is not possible to use quicklens on it:

import com.softwaremill.quicklens.*

object Types {
  case class V(x: Double, y: Double)

  opaque type Vec = V

  object Vec {
    def apply(x: Double, y: Double): Vec = V(x, y)
  }
  extension (v: Vec) {
    def x: Double = v.x
    def y: Double = v.y
    def copy(x: Double = v.x, y: Double = v.y): Vec = V(x, y)
  }
}

object Main {
  import Types.*
  def main(args: Array[String]): Unit = {
    val a = Vec(1, 2)
    val b = a.modify(_.x).using(_ + 1)
    println(b)
  }

}

With Scala 3.4.2 the error is:

Unsupported path element. Path must have shape: .field1.field2.each.field3.(...), got: (($1: Types.Vec) => Types.x($1))
val b = a.modify(.x).using(_ + 1)

[OndrejSpanel]

It is not only opaque types. Following wrapper gives the same error:

import com.softwaremill.quicklens.*

object Types {
  case class V(x: Double, y: Double)

  class Vec(val v: V)

  object Vec {
    def apply(x: Double, y: Double): Vec = new Vec(V(x, y))
  }
  extension (v: Vec) {
    def x: Double = v.v.x
    def y: Double = v.v.y
    def copy(x: Double = v.x, y: Double = v.y): Vec = new Vec(V(x, y))
  }
}

object Main {
  import Types.*
  def main(args: Array[String]): Unit = {
    val a = Vec(1, 2)
    val b = a.modify(_.x).using(_ + 1)
    println(b)
  }

}

[OndrejSpanel]

And when I remove extension and use members instead, the code works in Scala 2.13.14, but not in Scala 3:

import com.softwaremill.quicklens._

object Types {
  case class V(x: Double, y: Double)

  class Vec(val v: V) {
    def x: Double = v.x
    def y: Double = v.y
    def copy(x: Double = v.x, y: Double = v.y): Vec = new Vec(V(x, y)) {}
  }

  object Vec {
    def apply(x: Double, y: Double): Vec = new Vec(V(x, y)) {}
  }
}

object Main {
  import Types._
  def main(args: Array[String]): Unit = {
    val a = Vec(1, 2)
    val b = a.modify(_.x).using(_ + 1)
    println(b)
  }

}

The error in Scala 3 is:

Unsupported source object: must be a case class or sealed trait, but got: val
val b = a.modify(.x).using( + 1)