refactor(nix): simplify package declaration

flake.nix

@@ -41,36 +41,22 @@
         };
       in {
         formatter = alejandra.defaultPackage.${system};
-        packages =
+        packages = let
-          (import ./nix/package.nix {inherit pkgs rustPlatform;})
+          nativeRustVersion = pkgs.rust-bin.stable.latest.default;
-          // {
+          nativeRustPlatform = pkgs.makeRustPlatform {
-            windows = let
+            cargo = nativeRustVersion;
+            rustc = nativeRustVersion;
+          };
           mingwPkgs = pkgs.pkgsCross.mingwW64;
-              rustWindows = pkgs.rust-bin.stable.latest.default.override {
+          windowsRustVersion = pkgs.rust-bin.stable.latest.default.override {
             targets = ["x86_64-pc-windows-gnu"];
           };
-              rustPlatformWindows = mingwPkgs.makeRustPlatform {
+          windowsRustPlatform = mingwPkgs.makeRustPlatform {
-                cargo = rustWindows;
+            cargo = windowsRustVersion;
-                rustc = rustWindows;
+            rustc = windowsRustVersion;
           };
-              cargoToml = builtins.fromTOML (builtins.readFile ./Cargo.toml);
         in
-              rustPlatformWindows.buildRustPackage {
+          import ./nix/package.nix {inherit pkgs nativeRustPlatform windowsRustPlatform;};
-                pname = cargoToml.package.name;
-                version = cargoToml.package.version;
-                src = pkgs.lib.cleanSource ./.;
-                cargoLock.lockFile = ./Cargo.lock;
-                nativeBuildInputs = [pkgs.upx];
-                doCheck = false;
-                meta = {
-                  description = "Conventional commits for Jujutsu";
-                  homepage = "https://labs.phundrak.com/phundrak/jj-cz";
-                };
-                postBuild = ''
-                  ${pkgs.upx}/bin/upx target/*/release/jj-cz.exe
-                '';
-              };
-          };
         devShell = import ./nix/shell.nix {
           inherit inputs pkgs rustVersion;
         };

nix/package.nix

@@ -1,26 +1,36 @@
 {
   pkgs,
-  rustPlatform,
+  nativeRustPlatform,
+  windowsRustPlatform,
   ...
 }: let
   cargoToml = fromTOML (builtins.readFile ../Cargo.toml);
   name = cargoToml.package.name;
   version = cargoToml.package.version;
-  rustBuild = rustPlatform.buildRustPackage {
+  buildArgs = {
     pname = name;
     inherit version;
     src = pkgs.lib.cleanSource ../.;
     cargoLock.lockFile = ../Cargo.lock;
-    nativeBuildInputs = [pkgs.upx];
     useNextest = true;
     meta = {
-      description = "Conventional commits for Jujutsu";
+      inherit (cargoToml.package) description homepage;
-      homepage = "https://labs.phundrak.com/phundrak/jj-cz";
     };
     postBuild = ''
       ${pkgs.upx}/bin/upx target/*/release/${name}
     '';
   };
+  nativeBuild =
+    nativeRustPlatform.buildRustPackage buildArgs
+    // {
+      postBuild = "${pkgs.upx}/bin/upx target/*/release/${name}";
+    };
+  windowsBuild =
+    windowsRustPlatform.buildRustPackage buildArgs
+    // {
+      postBuild = "${pkgs.upx}/bin/upx target/*/release/${name}.exe";
+    };
 in {
-  default = rustBuild;
+  default = nativeBuild;
+  windows = windowsBuild;
 }