Please show me this being used to debug a real program. Toy examples that don’t do any real work isn’t interesting. My confidence that this work for an actual program is approximately zero percent.
While I am not so negative, I'd also like to have a demo with a real example. Even if it does not scale, I think this could make debugging interesting at least for beginners and their smaller code bases. Rust is called a language that is hard for beginners, and I think every approach into easing things should be welcomed.