--- a/util/set.lua Fri Feb 16 08:23:15 2018 +0100
+++ b/util/set.lua Fri Feb 16 08:23:26 2018 +0100
@@ -12,7 +12,7 @@
local _ENV = nil;
-local set_mt = {};
+local set_mt = { __name = "set" };
function set_mt.__call(set, _, k)
return next(set._items, k);
end