"setmetatable" and "getmetatable" are not available
setmetatable and getmetatable global functions are not available for usage in the current sandbox implementation. This makes it harder to create complex programs.
I assume they are absent due to security concerns. I believe that setting the __metatable field in all internal tables should suffice to protect them (see http://www.lua.org/manual/5.1/manual.html#pdf-setmetatable).
I can provide an implementation if this feature is desirable.
Thanks, Yes, the reason was security. I'm very busy at the moment, so I won't be able to look into this any time soon. If you want the feature in trAInsported, it'd be great if you could provide an implementation!
Be sure to sandbox __gc as it runs outside of the debug hooks that limit execution time