never seen that before. It seems nice, I may use it some day.

It doesn't solve my Lua issue unfortunately - I need several versions of lua - and fengari seems to implement lua 5.3.

Also the lua thing is just an example. I had many of such "not trivial, not too much" + "i don't really care, i need an answer and never go back to it" situations. I still long for StackOverflow with money offer for a solution.