When I worked for Prisma, you can check our rust setup from the public flake:

https://github.com/prisma/prisma-engines/blob/main/flake.nix

CD to the project and nix-direnv loads the flake. Get to work.

Now when I’m working in Grafbase, our flake is a bit different:

https://github.com/grafbase/grafbase/blob/main/flake.nix

Instead of the Rust overlay, we use rustup and rust-toolchain.toml. This makes it easier to enforce the same Rust version for nix and non-nix users.

Both ways work really well. The deal is to define the rust env per project instead of defining it globally. Use direnv to make it working seamlessly.