src/Tools/VSCode/src/build_vscode.scala

   /* grammar */
 
   def build_grammar(options: Options, progress: Progress = No_Progress)
   {
     val logic = Grammar.default_logic
-    val keywords = Build.outer_syntax(options, Nil, logic).keywords
+    val keywords = Build.session_base(options, logic).syntax.keywords
 
     val output_path = extension_dir + Path.explode(Grammar.default_output(logic))
     progress.echo(output_path.implode)
     File.write_backup(output_path, Grammar.generate(keywords))
   }