diff -r 38fefd98c929 -r 23de054397e5 src/HOL/Tools/Sledgehammer/sledgehammer_mash.ML
--- a/src/HOL/Tools/Sledgehammer/sledgehammer_mash.ML	Mon Mar 28 12:05:47 2016 +0200
+++ b/src/HOL/Tools/Sledgehammer/sledgehammer_mash.ML	Mon Mar 28 12:05:47 2016 +0200
@@ -834,7 +834,7 @@
   let
     val problem =
       {comment = "Goal: " ^ goal_name, state = Proof.init ctxt, goal = goal, subgoal = 1,
-       subgoal_count = 1, factss = [("", facts)]}
+       subgoal_count = 1, factss = [("", facts)], found_proof = I}
   in
     get_minimizing_prover ctxt MaSh (K ()) prover params problem
   end