An issue was discovered in the lever crate before 0.1.1 for Rust. AtomicBox<T> implements the Send and Sync traits for all types T.
https://rustsec.org/advisories/RUSTSEC-2020-0137.html
https://raw.githubusercontent.com/rustsec/advisory-db/main/crates/lever/RUSTSEC-2020-0137.md