t2106.scala:7: warning: Could not inline required method foo because access level required by callee not matched by caller.
  def main(args: Array[String]): Unit = x.foo
                                          ^
t2106.scala:7: warning: At the end of the day, could not inline @inline-marked method foo
  def main(args: Array[String]): Unit = x.foo
                                          ^