src/Pure/Build/build_benchmark.scala

     val options = Options.Spec.eq("build_hostname", host.name) :: host.options
     ssh.bash_path(Isabelle_Tool.exe(isabelle_home)) + " build_benchmark" +
       Options.Spec.bash_strings(options, bg = true)
   }
 
-  def benchmark_requirements(options: Options, progress: Progress = new Progress()): Unit = {
+  def benchmark_requirements(options: Options, progress: Progress = new Progress): Unit = {
     val res =
       Build.build(
         options.string.update("build_engine", Build.Default_Engine.name),
         selection = Sessions.Selection(requirements = true, sessions = List(benchmark_session)),
         progress = progress, build_heap = true)
     if (!res.ok) error("Failed building requirements")
   }
 
-  def benchmark(options: Options, progress: Progress = new Progress()): Unit = {
+  def benchmark(options: Options, progress: Progress = new Progress): Unit = {
     val hostname = options.string("build_hostname")
     val store = Store(options)
 
     using(store.open_server()) { server =>
       using_optional(store.maybe_open_database_server(server = server)) { database_server =>