@@ -281,6 +281,7 @@ eval traceon ctxt ntimes genv tm opts = ev ntimes [] True [] tm where
281281 Just (altmap, sc) -> evTree ntimes stk top env altmap sc
282282 _ -> return Nothing
283283 _ -> return Nothing
284+ evTree ntimes stk top env amap ImpossibleCase = return Nothing
284285
285286 conHeaded tm@(App _ _)
286287 | (P (DCon _ _) _ _, args) <- unApply tm = True