diff -r 4f91262e7f33 -r fd533ac64390 src/Pure/System/isabelle_system.scala
--- a/src/Pure/System/isabelle_system.scala	Fri May 17 21:06:01 2013 +0200
+++ b/src/Pure/System/isabelle_system.scala	Fri May 17 21:15:33 2013 +0200
@@ -354,6 +354,7 @@
     def out: String = cat_lines(out_lines)
     def err: String = cat_lines(err_lines)
     def add_err(s: String): Bash_Result = copy(err_lines = err_lines ::: List(s))
+    def set_rc(i: Int): Bash_Result = copy(rc = i)
   }
 
   def bash_env(cwd: JFile, env: Map[String, String], script: String,