rust’s borrow checker, but it looks at code and says things like "you appear to be building an open proxy server" or "this looks like a novel encryption scheme" and follows it with "are you sure this is safe?" and then forces you to re-run the build with —I-am-responsible-for-the-things-I-create flag enabled.
@djsundog I bet someone could get a lot of those added to clippy. Not the last part, unfortunately, but we need more dev tools that pop up saying "It looks like you're trying to ___. Please stop."