src/Tools/VSCode/src/build_vscode.scala

   val extension_dir = Path.explode("~~/src/Tools/VSCode/extension")
 
 
   /* grammar */
 
-  def build_grammar(options: Options, progress: Progress = No_Progress)
+  def build_grammar(options: Options, progress: Progress = new Progress)
   {
     val logic = Grammar.default_logic
     val keywords = Sessions.base_info(options, logic).check_base.overall_syntax.keywords
 
     val output_path = extension_dir + Path.explode(Grammar.default_output(logic))

   }
 
 
   /* extension */
 
-  def build_extension(progress: Progress = No_Progress, publish: Boolean = false)
+  def build_extension(progress: Progress = new Progress, publish: Boolean = false)
   {
     val output_path = extension_dir + Path.explode("out")
     progress.echo(output_path.implode)
 
     progress.bash(