But it didn't promise to be the solution either. Rust has never claimed, nor have its advocates claimed, that unsafe Rust can eliminate memory bugs. Safe Rust can do that (assuming any unsafe code relied upon is sound), but unsafe cannot be and has never promised to be bug free.

Except that it didn't fail to be the solution: the bug is localized to an explicit escape hatch in Rust's safety rules, rather than being a latent property of the system.

(I think the underlying philosophical disagreement here is this: I think software is always going to have bugs, and that Rust can't - and doesn't promise - to perfectly eliminate them. Instead, what Rust does promise - and deliver on - is that the entire class of memory safety bugs can be eliminated by construction in safe Rust, and localized when present to errors in unsafe Rust. Insofar as that's the promise, Rust has delivered here.)