src/Tools/jEdit/src/debugger_dockable.scala

     Session.Consumer[Any](getClass.getName) {
       case _: Session.Global_Options =>
         Debugger.set_session(PIDE.session)
         GUI_Thread.later { handle_resize() }
 
-      case _: Debugger.Update =>
+      case Debugger.Update =>
         GUI_Thread.later { handle_update() }
     }
 
   override def init()
   {