It's surprising this bug went unnoticed for so long, but at least it's easy to fix, since it's not a bug with the type system itself; it's just a bug in the compiler. The compiler should always have been rejecting that code according to lifetime rules of Rust's type system, so the fix is to just make it reject the code, rather than having to change the fundamental rules of lifetimes.
Not knowing anything about rust, the problem in these type of case is making it rejecting that bad code without also rejecting valid programs. But maybe this is indeed easy to fix, I don't know.
It's fascinating that this kind of bug is exactly you can't really avoid even when rust is supposedly to guard against. Rust mitigated this problem a lot in practice, but you can never be certain because of issues like this in practice. This is similar that a math proof that's already been peer reviewed and accepted as truth, may still be possible to be wrong, although the chance is very small but it's not zero. Epseicially when the complexity gets higher.