t9629.scala:4: error: pattern must be a value: Option[Int]
Note: if you intended to match against the class, try `case _: Option[_]`
      case Option[Int] => // error was issued before
                 ^
t9629.scala:5: error: pattern must be a value: Option[Int]
Note: if you intended to match against the class, try `case _: Option[_]`
      case Some(Option[Int]) => // error was skipped, patmat issued an internal error
                      ^
t9629.scala:8: error: pattern must be a value: Option[Int]
Note: if you intended to match against the class, try `case _: Option[_]`
      case (_, Option[Int]) =>
                     ^
t9629.scala:9: error: pattern must be a value: Option[Int]
Note: if you intended to match against the class, try `case _: Option[_]`
      case x @ (y @ Option[Int]) =>
                          ^
four errors found