The main issue I've come across is that when dealing with multi-crate projects, it is not uncommon to have two versions of the exact same version number of a Ru

The main issue I've come across is that when dealing with multi-crate projects, it is not uncommon to have two versions of the exact same version number of a Rust crate in two different dependencies. Due to a limitation in the machinery, this is painful. The other thing that's weird is that you have to embed the lockfile into the Nix derivative, at least in some cases. I actually can't remember why that has to be done, but presumably there is a good reason. I think most multi-crate projects are only sorta accidentally including multiple versions of the same crate, which is why it's rather unfortunate that there isn't some abstraction between crate and module.