In reply to @ralith:ralith.com
to kick off topical discussion, of the assorted tools, https://github.com/kolloch/crate2nix seems to work quite nicely at the moment

I'm a fan of https://github.com/nix-community/naersk but it doesn't build libraries because they don't check in a Cargo.lock which is what it exploits to make builds reproducible. My biggest qualm with the rust support in nix so far is the library integration. Everything is great for building and shipping executables but there is a lack of support for libraries in my opinion. I haven't found a workflow or tool yet that allows me to make cargo "nix aware" e.g. "cargo build" fetches build artifacts from the nix-store.

Admittedly, I only understand the rust build system and dependency management at a high level so I don't know how feasible this would be.