[josephg]

> do you need a borrow checker for `ls`? Probably not.

Does ls use references and objects with lifetimes? I bet it does. And if so, the answer is yes. You do need the borrow checker in rust to make sure it uses memory and lifetimes correctly.

If your program somehow doesn’t use references or owned objects, then the borrow checker doesn’t have any work to do. So there’s no harm done in leaving it on.