diff -r d8ff14f44a40 -r fd9e28d5a143 src/Pure/System/options.scala
--- a/src/Pure/System/options.scala	Mon Jul 23 22:35:10 2012 +0200
+++ b/src/Pure/System/options.scala	Tue Jul 24 00:29:36 2012 +0200
@@ -79,6 +79,11 @@
     }
     options
   }
+
+
+  /* encode */
+
+  val encode: XML.Encode.T[Options] = (options => options.encode)
 }