[ralfj]

If you are writing unsafe Rust code and want to be sure that your code is following the rules of the language, then this is an important steps towards giving you a sufficiently precise description of those rules that you can use for this purpose.

If you are writing a Rust compiler or a Rust verification tool, then a spec like MiniRust is a key part of telling you whether you got it right.

If you are not doing either of these things then you probably don't have a use-case for MiniRust. :)