An issue was discovered in the slock crate through 2020-11-17 for Rust. Slock<T> unconditionally implements Send and Sync.
https://rustsec.org/advisories/RUSTSEC-2020-0135.html
https://raw.githubusercontent.com/rustsec/advisory-db/main/crates/slock/RUSTSEC-2020-0135.md