src/Pure/System/isabelle_process.ML

--- a/src/Pure/System/isabelle_process.ML	Sat Mar 18 12:24:56 2017 +0100
+++ b/src/Pure/System/isabelle_process.ML	Sat Mar 18 12:46:52 2017 +0100
@@ -205,7 +205,9 @@
     val channel = System_Channel.rendezvous socket;
     val msg_channel = init_channels channel;
     val _ = loop channel;
-  in Message_Channel.shutdown msg_channel end);
+    val _ = Message_Channel.shutdown msg_channel;
+    val _ = Private_Output.init_channels ();
+  in () end);
 
 
 (* init options *)