refactor: simplify flake.nix structure and improve go binary derivation

Author: karol-broda

flake.lock

@@ -1,107 +1,105 @@
 {
   description = "snitch - a friendlier ss/netstat for humans";
 
-  inputs = {
-    nixpkgs.url = "github:NixOS/nixpkgs/nixos-25.05";
-    systems.url = "github:nix-systems/default";
-  };
+  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-25.05";
 
-  outputs = { self, nixpkgs, systems }:
+  outputs = { self, nixpkgs }:
     let
-      supportedSystems = import systems;
-      forAllSystems = f: nixpkgs.lib.genAttrs supportedSystems (system: f system);
+      systems = [ "x86_64-linux" "aarch64-linux" "x86_64-darwin" "aarch64-darwin" ];
+      eachSystem = nixpkgs.lib.genAttrs systems;
 
-      # go 1.25 overlay (required until nixpkgs has it)
-      goOverlay = final: prev:
+      # go 1.25 binary derivation (required until nixpkgs ships it)
+      mkGo125 = pkgs:
         let
           version = "1.25.0";
-          platformInfo = {
-            "x86_64-linux" = { suffix = "linux-amd64"; sri = "sha256-KFKvDLIKExObNEiZLmm4aOUO0Pih5ZQO4d6eGaEjthM="; };
-            "aarch64-linux" = { suffix = "linux-arm64"; sri = "sha256-Bd511plKJ4NpmBXuVTvVqTJ9i3mZHeNuOLZoYngvVK4="; };
-            "x86_64-darwin" = { suffix = "darwin-amd64"; sri = "sha256-W9YOgjA3BiwjB8cegRGAmGURZxTW9rQQWXz1B139gO8="; };
-            "aarch64-darwin" = { suffix = "darwin-arm64"; sri = "sha256-VEkyhEFW2Bcveij3fyrJwVojBGaYtiQ/YzsKCwDAdJw="; };
-          };
-          hostSystem = prev.stdenv.hostPlatform.system;
-          chosen = platformInfo.${hostSystem} or (throw "unsupported system: ${hostSystem}");
+          platform = {
+            "x86_64-linux" = { suffix = "linux-amd64"; hash = "sha256-KFKvDLIKExObNEiZLmm4aOUO0Pih5ZQO4d6eGaEjthM="; GOOS = "linux"; GOARCH = "amd64"; };
+            "aarch64-linux" = { suffix = "linux-arm64"; hash = "sha256-Bd511plKJ4NpmBXuVTvVqTJ9i3mZHeNuOLZoYngvVK4="; GOOS = "linux"; GOARCH = "arm64"; };
+            "x86_64-darwin" = { suffix = "darwin-amd64"; hash = "sha256-W9YOgjA3BiwjB8cegRGAmGURZxTW9rQQWXz1B139gO8="; GOOS = "darwin"; GOARCH = "amd64"; };
+            "aarch64-darwin" = { suffix = "darwin-arm64"; hash = "sha256-VEkyhEFW2Bcveij3fyrJwVojBGaYtiQ/YzsKCwDAdJw="; GOOS = "darwin"; GOARCH = "arm64"; };
+          }.${pkgs.stdenv.hostPlatform.system} or (throw "unsupported system: ${pkgs.stdenv.hostPlatform.system}");
         in
-        {
-          go_1_25 = prev.stdenvNoCC.mkDerivation {
-            pname = "go";
-            inherit version;
-            src = prev.fetchurl {
-              url = "https://go.dev/dl/go${version}.${chosen.suffix}.tar.gz";
-              hash = chosen.sri;
-            };
-            dontBuild = true;
-            installPhase = ''
-              runHook preInstall
-              mkdir -p "$out"/{bin,share}
-              tar -C "$TMPDIR" -xzf "$src"
-              cp -a "$TMPDIR/go" "$out/share/go"
-              ln -s "$out/share/go/bin/go" "$out/bin/go"
-              ln -s "$out/share/go/bin/gofmt" "$out/bin/gofmt"
-              runHook postInstall
-            '';
-            dontPatchELF = true;
-            dontStrip = true;
+        pkgs.stdenv.mkDerivation {
+          pname = "go";
+          inherit version;
+          src = pkgs.fetchurl {
+            url = "https://go.dev/dl/go${version}.${platform.suffix}.tar.gz";
+            inherit (platform) hash;
+          };
+          dontBuild = true;
+          dontPatchELF = true;
+          dontStrip = true;
+          installPhase = ''
+            runHook preInstall
+            mkdir -p $out/{bin,share/go}
+            tar -xzf $src --strip-components=1 -C $out/share/go
+            ln -s $out/share/go/bin/go $out/bin/go
+            ln -s $out/share/go/bin/gofmt $out/bin/gofmt
+            runHook postInstall
+          '';
+          passthru = {
+            inherit (platform) GOOS GOARCH;
           };
         };
-    in
-    {
-      overlays.default = final: prev: {
-        snitch = final.callPackage ./nix/package.nix { };
-      };
 
-      packages = forAllSystems (system:
-        let
-          pkgs = import nixpkgs {
-            inherit system;
-            overlays = [ goOverlay ];
-          };
-        in
+      pkgsFor = system: import nixpkgs { inherit system; };
+
+      mkSnitch = pkgs:
         let
           version = self.shortRev or self.dirtyShortRev or "dev";
+          go = mkGo125 pkgs;
+          buildGoModule = pkgs.buildGoModule.override { inherit go; };
         in
-        {
-          default = pkgs.buildGoModule {
-            pname = "snitch";
-            inherit version;
-            src = self;
-            vendorHash = "sha256-fX3wOqeOgjH7AuWGxPQxJ+wbhp240CW8tiF4rVUUDzk=";
-            env.CGO_ENABLED = 0;
-            ldflags = [
-              "-s" "-w"
-              "-X snitch/cmd.Version=${version}"
-              "-X snitch/cmd.Commit=${version}"
-              "-X snitch/cmd.Date=${self.lastModifiedDate or "unknown"}"
-            ];
-            meta = with pkgs.lib; {
-              description = "a friendlier ss/netstat for humans";
-              homepage = "https://github.com/karol-broda/snitch";
-              license = licenses.mit;
-              platforms = platforms.linux;
-              mainProgram = "snitch";
-            };
+        buildGoModule {
+          pname = "snitch";
+          inherit version;
+          src = self;
+          vendorHash = "sha256-fX3wOqeOgjH7AuWGxPQxJ+wbhp240CW8tiF4rVUUDzk=";
+          env.CGO_ENABLED = "0";
+          env.GOTOOLCHAIN = "local";
+          ldflags = [
+            "-s"
+            "-w"
+            "-X snitch/cmd.Version=${version}"
+            "-X snitch/cmd.Commit=${version}"
+            "-X snitch/cmd.Date=${self.lastModifiedDate or "unknown"}"
+          ];
+          meta = {
+            description = "a friendlier ss/netstat for humans";
+            homepage = "https://github.com/karol-broda/snitch";
+            license = pkgs.lib.licenses.mit;
+            platforms = pkgs.lib.platforms.linux;
+            mainProgram = "snitch";
           };
+        };
+    in
+    {
+      packages = eachSystem (system:
+        let pkgs = pkgsFor system; in
+        {
+          default = mkSnitch pkgs;
+          snitch = mkSnitch pkgs;
         }
       );
 
-      devShells = forAllSystems (system:
+      devShells = eachSystem (system:
         let
-          pkgs = import nixpkgs {
-            inherit system;
-            overlays = [ goOverlay ];
-          };
+          pkgs = pkgsFor system;
+          go = mkGo125 pkgs;
         in
         {
           default = pkgs.mkShell {
-            packages = [ pkgs.go_1_25 pkgs.git pkgs.vhs ];
-            GOTOOLCHAIN = "local";
+            packages = [ go pkgs.git pkgs.vhs ];
+            env.GOTOOLCHAIN = "local";
             shellHook = ''
               echo "go toolchain: $(go version)"
             '';
           };
         }
       );
+
+      overlays.default = final: _prev: {
+        snitch = mkSnitch final;
+      };
     };
 }