`given` limitation under `-Xsource:3`

[som-snytt]

Reproduction steps

Scala version: 2.13.15

//> using options -Xsource:3
import scala.util.chaining.given
import scala.concurrent.duration.given

class C {
  def f = 42.tap(println)
  def g = 42.seconds
}

Problem

chaining works but duration does not.