src/Pure/Tools/update_cartouches.scala

         if (ants == ants1) content else ants1.map(_.source).mkString
       case None => content
     }
   }
 
-  def update_cartouches(replace_text: Boolean, path: Path)
+  def update_cartouches(replace_text: Boolean, path: Path): Unit =
   {
     val text0 = File.read(path)
 
     // outer syntax cartouches
     val text1 =