diff -r 76b814ccce61 -r c35012b86e6f src/Pure/System/isabelle_process.scala
--- a/src/Pure/System/isabelle_process.scala	Tue Mar 29 22:22:12 2016 +0200
+++ b/src/Pure/System/isabelle_process.scala	Tue Mar 29 23:41:28 2016 +0200
@@ -13,6 +13,7 @@
     options: Options,
     logic: String = "",
     args: List[String] = Nil,
+    dirs: List[Path] = Nil,
     modes: List[String] = Nil,
     receiver: Prover.Receiver = Console.println(_),
     store: Sessions.Store = Sessions.store()): Isabelle_Process =
@@ -20,8 +21,8 @@
     val channel = System_Channel()
     val process =
       try {
-        ML_Process(options, logic = logic, args = args, modes = modes, store = store,
-          channel = Some(channel))
+        ML_Process(options, logic = logic, args = args, dirs = dirs,
+          modes = modes, store = store, channel = Some(channel))
       }
       catch { case exn @ ERROR(_) => channel.accepted(); throw exn }
     process.stdin.close