In my very large Rust-based project of about 100k lines of code, 100 direct dependencies, and 800 total dependencies, I always require version="*" for each dependency, except for specific ones that either I cannot or don’t want to upgrade.
Crucially, I also commit my Cargo.lock, as the Cargo manual recommends.
I normally build with cargo --locked. Periodically, I will do a cargo update and run cargo outdated so that I’m able to see if there are specific packages keeping me at older versions.
To upgrade a specific package, I can just remove its record directly from Cargo.lock and then do a regular cargo build.
This works very well!
Advantages
- I minimize my number of dependencies, and therefor build times
- I keep my personal ecosystem from falling too far behind that of crates.io
- I rarely wind up with a situation where I have two dependencies that depend on a different symbol version
- I don’t have to change a version in all of my many
Cargo.tomls
Disadvantages
- I cannot publish my large repository to a wider audience (but that will never happen for this repository)
- People who see my code start feeling ill and start shifting their eyes nervously.
Yes, it’s true that for each
cargo update, I have to study the list of updates reasonably closely, and then I may have some compile fixes as well. Those are quite rare, and 9/10 times, there’s nothing to do but the update.