By my count, there are now no less than 6 different solutions for building Rust code with Nix. In an effort to help people choose one, and start a discussion on hopefully standardizing on something to include in Nixpkgs, here’s my effort to compare what’s out there. I should note that most of this information is based on documentation and occasional peeks at the code; I haven’t actually tested most of these solutions.
Here’s what all the columns mean:
- Cargo.lock solution: How does this solution handle reproducibly determining what crates need to be downloaded from the Cargo.lock file? “Checksum” means it requires you to specify the checksum of all the downloaded dependencies. “Import” means it dynamically imports and parses Cargo.lock from a Nix expression, which means Cargo.lock needs to be present in the same repository as the nix expressions (or IFD must be used). “Codegen” means it generates a .nix file from the Cargo.lock, which is then committed to source control.
- Derivations: How many derivations does this solution use to compile rust code? “1” means the project and all its dependencies are compiled in one derivation. “2” means all dependencies are moved into a separate derivation, so the project can be updated independently, but any change to the set of dependencies rebuilds everything. “Many” means each dependency is built in its own derivation, so changes to dependencies only do the minimal amount of rebuilding necessary (and, ideally, different projects can share dependences, although I haven’t checked if this works in practice).
Build logic: How does this solution orchestrate building of crates? “Cargo” means it relies on Cargo;
buildRustCratemeans it uses Nixpkgs’
buildRustCrate; “custom” means it uses its own custom logic (in Nix)
- Supports cross: Does the solution allow for cross-compilation of crates?
|Name||Cargo.lock solution||Derivations||Build logic||Supports cross||Notes|
||Checksum||1||cargo||Yes||Built into nixpkgs|
||No?||Unmaintained, AFAICT; repository is gone|
||Codegen (with optional IFD)||Many||
||No||Spiritual successor to carnix; nobody currently spending much time maintaining it|
||Import||2||cargo||No?||Seems to only support building on x86|
||Codegen||Many||Custom||Yes||Seems to only support prebuilt rustc from the
||Import||1||cargo||Unclear||More of a proof of concept than a full working solution|