I could be wrong, but the Ferrocene Language Specification, FLS, adopted by Rust as its specification, may be severely incomplete.
For instance, it describes atomics, but I am not sure that it defines Rust's memory model or the semantics of atomics anywhere.
This Ferrocene page looks very short, and has a lot of links to Rust API documentation.
https://public-docs.ferrocene.dev/main/specification/concurr...
Conversely, the Rustonomicon has this page that says that Rust just uses C++20's memory model for its atomics. Yet I do not believe that memory model is defined anywhere in FLS.
https://doc.rust-lang.org/nomicon/atomics.html
I do not know if FLS defines unwinding of panics anywhere either.
Is FLS severely incomplete regarding rustc and Rust, despite being adopted by Rust as its specification? It almost seems fake.
It is certainly incomplete. Virtually all specifications for programming languages are. It is good enough for safety critical work, which is a higher bar than most.
The idea is that you adopt them and improve them over time. It is more complete than the reference, which is the previous project in this area.