--- a/src/Pure/Tools/build.ML Wed Apr 06 11:37:37 2016 +0200
+++ b/src/Pure/Tools/build.ML Wed Apr 06 11:44:34 2016 +0200
@@ -193,3 +193,5 @@
in Output.protocol_message (Markup.build_theories_result id) [result] end);
end;
+
+structure Output: OUTPUT = Output; (*seal system channels!*)