Print errors (Failure exceptions) nicely.

diff --git a/src/main.ml b/src/main.ml
index b95d1f5..73a53da 100644 (file)
--- a/src/main.ml
+++ b/src/main.ml
@@ -97,4 +97,7 @@ let main () =
   (* Evaluate the target expressions in turn. *)
   Eval.evaluate_targets env targets
 
-let () = main ()
+let () =
+  try main ()
+  with
+    Failure msg -> prerr_endline msg; exit 1