rust-overlay

Pure and reproducible packaging of binary distributed rust toolchains. A compatible but better replacement for rust overlay of nixpkgs-mozilla, with also non-overlay and Nix Flake interfaces (despite the project name).

For migration from nixpkgs-mozilla, see this section.

Features:

Hashes of toolchain components are pre-fetched in tree, so the evaluation is pure and no need to have network access.
These hashes are auto-updated daily using GitHub Actions.
Current oldest supported stable version is 1.29.0 which are randomly picked.

Stable versions will not be purged currently.
Current oldest supported nightly version is 2023-01-01.

To prevent significant repository size bloating, our current strategy is keep only nightly and beta versions not earlier than {current_year - 1}-01-01. Earlier versions may be accessed via old snapshot tags.
We targets nixos-unstable and supported releases of NixOS, on x86_64-linux. They are tested on CI. Other platforms and nixpkgs channels may also work but is not guaranteed.

Documentations:

Installation

Classic Nix overlay

You can put the code below into your ~/.config/nixpkgs/overlays.nix.

[ (import (builtins.fetchTarball "https://github.com/oxalica/rust-overlay/archive/master.tar.gz")) ]

Then the provided attribute paths are available in nix command.

$ nix-env -iA nixpkgs.rust-bin.stable.latest.default # `nixpkgs` (or `nixos`) is your nixpkgs channel name.

Alternatively, you can install it into nix channels.

$ nix-channel --add https://github.com/oxalica/rust-overlay/archive/master.tar.gz rust-overlay
$ nix-channel --update

And then feel free to use it anywhere like import <nixpkgs> { overlays = [ (import <rust-overlay>) ]; } in your nix shell environment.

Nix Flakes

Warning: Only the output overlay/overlays are currently stable. Use other outputs at your own risk!

For a quick play, just use nix shell to bring the latest stable rust toolchain into scope. (All commands below requires preview version of Nix with flake support.)

$ nix shell github:oxalica/rust-overlay
$ rustc --version # This is only an example. You may get a newer version here.
rustc 1.49.0 (e1884a8e3 2020-12-29)
$ cargo --version
cargo 1.49.0 (d00d64df9 2020-12-05)

Use in NixOS Configuration

Here's an example of using it in nixos configuration.

{
  description = "My configuration";

  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
    rust-overlay = {
      url = "github:oxalica/rust-overlay";
      inputs.nixpkgs.follows = "nixpkgs";
    };
  };

  outputs = { nixpkgs, rust-overlay, ... }: {
    nixosConfigurations = {
      hostname = nixpkgs.lib.nixosSystem {
        system = "x86_64-linux";
        modules = [
          ./configuration.nix # Your system configuration.
          ({ pkgs, ... }: {
            nixpkgs.overlays = [ rust-overlay.overlays.default ];
            environment.systemPackages = [ pkgs.rust-bin.stable.latest.default ];
          })
        ];
      };
    };
  };
}

Use in `devShell` for `nix develop`

Running nix develop will create a shell with the default beta Rust toolchain installed:

{
  description = "A devShell example";

  inputs = {
    nixpkgs.url      = "github:NixOS/nixpkgs/nixos-unstable";
    rust-overlay.url = "github:oxalica/rust-overlay";
    flake-utils.url  = "github:numtide/flake-utils";
  };

  outputs = { self, nixpkgs, rust-overlay, flake-utils, ... }:
    flake-utils.lib.eachDefaultSystem (system:
      let
        overlays = [ (import rust-overlay) ];
        pkgs = import nixpkgs {
          inherit system overlays;
        };
      in
      {
        devShells.default = with pkgs; mkShell {
          buildInputs = [
            openssl
            pkg-config
            eza
            fd
            rust-bin.beta.latest.default
          ];

          shellHook = ''
            alias ls=eza
            alias find=fd
          '';
        };
      }
    );
}

Migration from nixpkgs-mozilla

Change the channel URL to https://github.com/oxalica/rust-overlay/archive/master.tar.gz, or flake URL to github:oxalica/rust-overlay for Nix Flakes.
Good to go! latest.*, rustChannel*.* and friends are made compatible with nixpkgs-mozilla. You don't necessary need to change anything.
You can also optionally change to the rust-bin interface, which provides more functionality like "latest nightly with specific components available" or "from rust-toolchain file". It also has nix-aware cross-compilation support.

Cheat sheet: common usage of `rust-bin`

Latest stable or beta rust profile.

rust-bin.stable.latest.default # Stable rust, default profile. If not sure, always choose this.
rust-bin.beta.latest.default   # Wanna test beta compiler.
rust-bin.stable.latest.minimal # I don't need anything other than rustc, cargo, rust-std. Bye rustfmt, clippy, etc.
rust-bin.beta.latest.minimal

It provides the same components as which installed by rustup install's default or minimal profiles.

Almost always, default is what you want for development.

Note: For difference between default and minimal profiles, see rustup - Profiles

Latest stable or beta rust profile, with extra components or target support.

rust-bin.stable.latest.default.override {
  extensions = [ "rust-src" ];
  targets = [ "arm-unknown-linux-gnueabihf" ];
}

Latest nightly rust profile.
```
rust-bin.selectLatestNightlyWith (toolchain: toolchain.default) # or `toolchain.minimal`
```
Note: Don't use rust-bin.nightly.latest. Your build would fail when some components missing on some days. Always use selectLatestNightlyWith instead.

Latest nightly rust profile, with extra components or target support.

rust-bin.selectLatestNightlyWith (toolchain: toolchain.default.override {
  extensions = [ "rust-src" ];
  targets = [ "arm-unknown-linux-gnueabihf" ];
})

A specific version of rust:

rust-bin.stable."1.48.0".default
rust-bin.beta."2021-01-01".default
rust-bin.nightly."2020-12-31".default

Note: All of them are override-able like examples above.

If you already have a rust-toolchain file for rustup, you can simply use fromRustupToolchainFile to get the customized toolchain derivation.
```
rust-bin.fromRustupToolchainFile ./rust-toolchain
```

Toolchain with specific rustc git revision.

This is useful for development of rust components like MIRI, which requires a specific revision of rust.

rust-bin.fromRustcRev {
  rev = "a2cd91ceb0f156cb442d75e12dc77c3d064cdde4";
  components = {
    rustc = "sha256-x+OkPVStX00AiC3GupIdGzWluIK1BnI4ZCBbg72+ZuI=";
    rust-src = "sha256-13PpzzYtd769Xkb0QzHpNfYCOnLMWFolc9QyYq98z2k=";
  };
}

Warning: This may not always work (including the example below) since upstream CI periodically purges old artifacts.

There also an cross-compilation example in examples/cross-aarch64.

License

MIT licensed.

oxalica/rust-overlay