Why gitignore Cargo.lock file?

[Tirka]

I dont think it’s a good idea to drop info about exact versions of project’s dependencies out of repository

[hardliner66]

It's good practice to not commit lock files when developing libraries
See:
https://doc.rust-lang.org/cargo/guide/cargo-toml-vs-cargo-lock.html
https://doc.rust-lang.org/cargo/faq.html#why-do-binaries-have-cargolock-in-version-control-but-not-libraries

[leenozara]

Recommended:

If you’re building a non-end product, such as a rust library that other rust packages will depend on, put Cargo.lock in your .gitignore. If you’re building an end product, which are executable like command-line tool or an application, or a system library with crate-type of staticlib or cdylib, check Cargo.lock into git.