diff -r d06c44532706 -r 89269bb8e7ca src/Pure/System/options.scala
--- a/src/Pure/System/options.scala	Tue Apr 22 12:05:02 2014 +0200
+++ b/src/Pure/System/options.scala	Tue Apr 22 12:30:54 2014 +0200
@@ -141,7 +141,7 @@
 
   def main(args: Array[String])
   {
-    Command_Line.tool {
+    Command_Line.tool0 {
       args.toList match {
         case get_option :: export_file :: more_options =>
           val options = (Options.init() /: more_options)(_ + _)
@@ -155,7 +155,6 @@
           if (get_option == "" && export_file == "")
             System.out.println(options.print)
 
-          0
         case _ => error("Bad arguments:\n" + cat_lines(args))
       }
     }