diff -r f6a2e5ce2ce5 -r 5f5649ac8235 src/Pure/Isar/parse_spec.ML
--- a/src/Pure/Isar/parse_spec.ML	Sun Aug 21 20:25:49 2011 +0200
+++ b/src/Pure/Isar/parse_spec.ML	Sun Aug 21 20:42:26 2011 +0200
@@ -136,7 +136,7 @@
     val expr0 = plus1_unless locale_keyword expr1;
   in expr0 -- Scan.optional (Parse.$$$ "for" |-- Parse.!!! locale_fixes) [] end;
 
-val context_element = Parse.group "context element" loc_element;
+val context_element = Parse.group (fn () => "context element") loc_element;
 
 end;