Could you please upgrade the rust compiler to the last version (1.33.0) and enable edition = “2018”? It’s easier to code in rust since NLL: https://blog.rust-lang.org/2018/12/06/Rust-1.31-and-rust-2018.html#non-lexical-lifetimes
time crate: no longer actively maintained, see https://github.com/rust-lang-deprecated/time. The author recommends using the chrono crate instead.
rand crate: a lot of work was done since 5.4, see https://github.com/rust-random/rand/blob/master/CHANGELOG.md
Compared to other languages (at least python and c++), we have not regex, could you please add the regex crate?
Maybe add lazy_static as suggested by https://www.codingame.com/forum/t/cannot-use-lazy-static-in-rust/87205