Nix flake build

.circleci/config.yml

@@ -46,7 +46,7 @@ commands:
     steps:
       - save_cache:
           name: "Save rustup cache"
-          key: cargo-v2-{{ checksum "rust-toolchain" }}-{{ checksum "Cargo.toml" }}-{{ checksum "Cargo.lock" }}-{{ arch }}
+          key: cargo-v2-{{ checksum "rust-toolchain.toml" }}-{{ checksum "Cargo.toml" }}-{{ checksum "Cargo.lock" }}-{{ arch }}
           paths:
             - "~/.cargo"
             - "~/.rustup"
@@ -55,7 +55,7 @@ commands:
       steps:
         - restore_cache:
             keys:
-              - cargo-v2-{{ checksum "rust-toolchain" }}-{{ checksum "Cargo.toml" }}-{{ checksum "Cargo.lock" }}-{{ arch }}
+              - cargo-v2-{{ checksum "rust-toolchain.toml" }}-{{ checksum "Cargo.toml" }}-{{ checksum "Cargo.lock" }}-{{ arch }}
 
   install_gpu_deps:
     steps:
@@ -69,10 +69,10 @@ jobs:
       - checkout
       - run:
           name: Update submodules
-          command: git submodule update --init --recursive
-      - run: curl https://sh.rustup.rs -sSf | sh -s -- -y
-      - run: rustup install $(cat rust-toolchain)
-      - run: rustup default $(cat rust-toolchain)
+          command: |
+            git submodule update --init --recursive
+            curl https://sh.rustup.rs -sSf | sh -s -- -y
+      - run: rustup show
       - run: cargo --version
       - run: rustc --version
       - run:
@@ -133,8 +133,7 @@ jobs:
           name: Install Rust
           command: |
             curl https://sh.rustup.rs -sSf | sh -s -- -y
-      - run: rustup install $(cat rust-toolchain)
-      - run: rustup default $(cat rust-toolchain)
+      - run: rustup show
       - run: cargo --version
       - run: cargo update
       - run: cargo fetch
@@ -157,8 +156,7 @@ jobs:
           name: Install Rust
           command: |
             curl https://sh.rustup.rs -sSf | sh -s -- -y
-      - run: rustup install $(cat rust-toolchain)
-      - run: rustup default $(cat rust-toolchain)
+      - run: rustup show
       - run: cargo --version
       - run: cargo update
       - run: cargo fetch

.envrc

@@ -0,0 +1 @@
+use flake

flake.nix

@@ -0,0 +1,45 @@
+{
+  inputs = {
+    nixpkgs.url = "nixpkgs/nixos-unstable";
+    flake-utils.url = "github:numtide/flake-utils";
+    naersk = {
+      url = "github:nix-community/naersk";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
+    fenix = {
+      url = "github:nix-community/fenix";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
+  };
+
+  outputs = { self, nixpkgs, flake-utils, naersk, fenix }:
+    flake-utils.lib.eachDefaultSystem (system:
+      let
+        pkgs = (import nixpkgs) {
+          inherit system;
+        };
+
+        toolchain = with fenix.packages.${system}; fromToolchainFile {
+          file = ./rust-toolchain.toml; # alternatively, dir = ./.;
+          sha256 = "sha256-riZUc+R9V35c/9e8KJUE+8pzpXyl0lRXt3ZkKlxoY0g=";
+        };
+
+      in rec {
+        defaultPackage = (naersk.lib.${system}.override {
+          # For `nix build` & `nix run`:
+          cargo = toolchain;
+          rustc = toolchain;
+        }).buildPackage {
+          src = ./.;
+        };
+
+        # For `nix develop` or `direnv allow`:
+        devShell = pkgs.mkShell {
+          buildInputs = with pkgs; [
+            ocl-icd
+            toolchain
+          ];
+        };
+      }
+    );
+}

rust-toolchain.toml

@@ -0,0 +1,7 @@
+[toolchain]
+channel = "1.67.0"
+targets = [ "aarch64-unknown-linux-gnu", "x86_64-unknown-linux-gnu", "x86_64-apple-darwin", "wasm32-unknown-unknown" ]
+components = [ "rustc", "cargo", "clippy", "rustfmt", "rust-src",
+"rust-analysis", "rust-analyzer" ]
+profile = "default"
+