How can I get access to a squatted crate name? (https://crates.io/crates/sail)

I have implemented the sail AST in Rust, as well as an interface for safely calling the OCaml functions of the Sail compiler in Rust, all as part of a project for my PhD (just mentioning because it means I'm committed to maintaining this for at least 3 years). I feel that releasing this crate would a good use of the sail name, as opposed to sail-rs or some other variation.

Unfortunately the crate name is being squatted; an empty package was published 5 years ago. I have been unable to contact the author via email, are there any systems in place to gain access to the crate for this kind of situation?