Illegal access error when constructor parameter has same name and more specific type

[travisbrown]

minimized code

trait Foo {
  def parent: Option[Foo]
  def getParent: Option[Foo] = parent
}

class Bar(val parent: Option[Foo]) extends Foo
class Qux(parent: Option[Qux]) extends Bar(parent)

object Qux {
  val qux: Qux = new Qux(None)

  def main(args: Array[String]): Unit = println(qux.getParent)
}

This code compiles, but crashes at runtime.

Exception in thread "main" java.lang.IllegalAccessError: Qux.parent()Lscala/Option;
        at Foo.getParent(Foo.scala:3)
        at Bar.getParent(Foo.scala:6)
        at Qux$.main(Foo.scala:12)
        at Qux.main(Foo.scala)

expectation

It should print None, like Scala 2 does. Note that changing Qux's constructor parameter name to something other than parent fixes the issue.