Scalatra jetty 9.1.3 issue with standalone deployment

Runner

object Runner {
  // this is my entry object as specified in sbt project definition
  def main(args: Array[String]) {
    val port = if (System.getenv("PORT") != null) System.getenv("PORT").toInt else 8080

    val server = new Server(port)

    val context = new WebAppContext()
    context setContextPath "/"
    context.setResourceBase("src/main/webapp")
    context.addEventListener(new ScalatraListener)
    context.addServlet(classOf[DefaultServlet], "/")

    server.setHandler(context)

    server.start()
    server.join()

  }
}

Scalatra routes

class SearchResource(private val searchService: SearchServiceInterface) extends ScalatraServlet with FutureSupport {

  protected implicit def executor: ExecutionContext = GlobalContext.system.dispatcher

  protected implicit def jsonFormats: Formats = DefaultFormats
  
  get("/") {
    new AsyncResult {
      val is = Future {

        val prom = Promise[String]()
        new Thread {
          Thread.sleep(500)
          prom.success("SUCCESS")
        }
        Ok(Await.result(prom.future, 10 seconds))
      }
    }
  }

}