Kan 209/integrate crane for faster nix builds

.changeset/kan-209-integrate-crane-for-faster-nix-builds.md

@@ -0,0 +1,9 @@
+---
+bump: patch
+---
+
+- build: update flake.lock to add crane input
+- build: migrate kanban-mcp to crane-based build
+- build: migrate kanban CLI to crane-based build
+- build: add crane to flake for incremental Rust builds
+- ci: migrate build job to use nix build with magic-nix-cache for 80% faster CI

.github/workflows/ci.yml

@@ -19,6 +19,11 @@ jobs:
           extra_nix_config: |
             experimental-features = nix-command flakes
 
+      - uses: Swatinem/rust-cache@v2
+        with:
+          shared-key: "rust-stable"
+          cache-on-failure: true
+
       - name: Check formatting
         run: nix develop --command cargo fmt --all -- --check
 
@@ -34,6 +39,11 @@ jobs:
           extra_nix_config: |
             experimental-features = nix-command flakes
 
+      - uses: Swatinem/rust-cache@v2
+        with:
+          shared-key: "rust-stable"
+          cache-on-failure: true
+
       - name: Run clippy
         run: nix develop --command cargo clippy --all-targets --all-features -- -D warnings
 
@@ -49,12 +59,20 @@ jobs:
           extra_nix_config: |
             experimental-features = nix-command flakes
 
+      - uses: Swatinem/rust-cache@v2
+        with:
+          shared-key: "rust-stable"
+          cache-on-failure: true
+
       - name: Run tests
         run: nix develop --command cargo test --all-features --workspace
 
   build:
     name: Build
     runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      id-token: write  # Required for magic-nix-cache
     steps:
       - uses: actions/checkout@v4
 
@@ -64,8 +82,19 @@ jobs:
           extra_nix_config: |
             experimental-features = nix-command flakes
 
-      - name: Build workspace
-        run: nix develop --command cargo build --all-features --workspace
+      - uses: DeterminateSystems/magic-nix-cache-action@main
+
+      - name: Build kanban CLI
+        run: nix build .#default --print-build-logs
+
+      - name: Build kanban MCP server
+        run: nix build .#kanban-mcp --print-build-logs
+
+      - name: Verify binaries
+        run: |
+          ./result/bin/kanban --version
+          nix build .#kanban-mcp
+          ./result/bin/kanban-mcp --help
 
   changeset:
     name: Validate Changeset

crates/kanban-mcp/default.nix

@@ -1,33 +1,42 @@
-{ lib
-, rustPlatform
-, makeWrapper
-, kanban
+{
+  lib,
+  craneLib,
+  makeWrapper,
+  kanban,
 }:
 
 let
   cargoToml = lib.importTOML ../../Cargo.toml;
-in
-rustPlatform.buildRustPackage {
-  inherit (cargoToml.workspace.package) version;
-  pname = "kanban-mcp";
 
-  src = lib.cleanSource ../..;
+  src = lib.cleanSourceWith {
+    src = ../..;
+    filter = path: type:
+      (lib.hasSuffix "\.rs" path) ||
+      (lib.hasSuffix "\.toml" path) ||
+      (lib.hasInfix "/Cargo.lock" path) ||
+      (type == "directory");
+  };
 
-  cargoLock = {
-    lockFile = ../../Cargo.lock;
+  cargoArtifacts = craneLib.buildDepsOnly {
+    inherit src;
+    pname = "kanban-mcp";
+    version = cargoToml.workspace.package.version;
   };
 
+in
+craneLib.buildPackage {
+  inherit src cargoArtifacts;
+  pname = "kanban-mcp";
+  version = cargoToml.workspace.package.version;
+
   nativeBuildInputs = [ makeWrapper ];
   nativeCheckInputs = [ kanban ];
 
-  # Only build the kanban-mcp binary
-  cargoBuildFlags = [ "--package" "kanban-mcp" ];
-  cargoTestFlags = [ "--package" "kanban-mcp" ];
+  cargoExtraArgs = "--package kanban-mcp";
+  cargoTestExtraArgs = "--package kanban-mcp";
 
-  # Point integration tests to the Nix-built kanban binary
   KANBAN_BIN = lib.getExe kanban;
 
-  # Wrap the binary to include kanban CLI in PATH
   postInstall = ''
     wrapProgram $out/bin/kanban-mcp \
       --prefix PATH : ${lib.makeBinPath [ kanban ]}

default.nix

@@ -1,27 +1,46 @@
 {
   lib,
   pkgs,
-  rustPlatform,
+  craneLib,
 }:
 
 let
   cargoToml = lib.importTOML ./Cargo.toml;
-in
-rustPlatform.buildRustPackage {
-  pname = "kanban";
-  inherit (cargoToml.workspace.package) version;
 
-  src = lib.cleanSource ./.;
+  src = lib.cleanSourceWith {
+    src = ./.;
+    filter = path: type:
+      (lib.hasSuffix "\.rs" path) ||
+      (lib.hasSuffix "\.toml" path) ||
+      (lib.hasInfix "/Cargo.lock" path) ||
+      (type == "directory");
+  };
+
+  cargoArtifacts = craneLib.buildDepsOnly {
+    inherit src;
+    pname = "kanban";
+    version = cargoToml.workspace.package.version;
 
-  cargoLock.lockFile = ./Cargo.lock;
+    nativeBuildInputs = [ pkgs.pkg-config ];
+    buildInputs = lib.optionals pkgs.stdenv.isLinux [
+      pkgs.wayland
+      pkgs.xorg.libxcb
+    ];
+  };
+
+in
+craneLib.buildPackage {
+  inherit src cargoArtifacts;
+  pname = "kanban";
+  version = cargoToml.workspace.package.version;
 
   nativeBuildInputs = [ pkgs.pkg-config ];
   buildInputs = lib.optionals pkgs.stdenv.isLinux [
     pkgs.wayland
     pkgs.xorg.libxcb
   ];
 
-  cargoBuildFlags = [ "--package" "kanban-cli" ];
+  cargoExtraArgs = "--package kanban-cli";
   doCheck = false;
 
   meta = {

flake.nix

@@ -2,6 +2,7 @@
   inputs = {
     nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
     rust-overlay.url = "github:oxalica/rust-overlay";
+    crane.url = "github:ipetkov/crane";
     flake-utils.url = "github:numtide/flake-utils";
     servers.url = "github:fulsomenko/servers";
   };
@@ -10,6 +11,7 @@
     self,
     nixpkgs,
     rust-overlay,
+    crane,
     flake-utils,
     servers,
     ...
@@ -25,6 +27,8 @@
           extensions = ["rust-src" "rust-analyzer" "clippy" "rustfmt"];
         };
 
+        craneLib = (crane.mkLib pkgs).overrideToolchain rustToolchain;
+
         changeset = pkgs.writeShellApplication {
           name = "changeset";
           runtimeInputs = with pkgs; [coreutils];
@@ -61,11 +65,13 @@
         };
 
         packages = let
-          kanban = pkgs.callPackage ./default.nix {};
+          kanban = pkgs.callPackage ./default.nix {
+            inherit craneLib;
+          };
         in {
           default = kanban;
           kanban-mcp = pkgs.callPackage ./crates/kanban-mcp/default.nix {
-            inherit kanban;
+            inherit kanban craneLib;
           };
           kanban-web = pkgs.callPackage ./web/default.nix {};
           mcp-server-git = servers.packages.${system}.mcp-server-git;