Help me to understand nested generics please

[lua-rocks]

This is example from tutorial, but I changed value 3 to "wtf" and I expected to get an error, because X in this case is a number and "wtf" is a string. But there are no errors. Why?

local record Tree<X>
  {Tree<X>}
  item: X
end

local t: Tree<number> = {
  item = 1,
  { item = 2 },
  { item = "wtf", { item = 4 } },
}

Also VSCode says that t[2].item is number 🙈

[hishamhm]

This was a bug and it's now fixed in #499! Thanks!