templates/rust-app: update

templates/rust-app/default.nix

@@ -1,37 +0,0 @@
-{ lib
-, rustPlatform
-, meson
-, ninja
-, pkg-config
-}:
-
-rustPlatform.buildRustPackage {
-  pname = "app";
-  version = "VERSION";
-
-  src = lib.fileset.toSource {
-    root = ./.;
-    fileset = lib.fileset.unions [
-      ./Cargo.lock
-      ./Cargo.toml
-      ./LICENSE
-      ./meson.build
-      ./meson_options.txt
-      ./src
-    ];
-  };
-
-  cargoLock.lockFile = ./Cargo.lock;
-
-  nativeBuildInputs = [
-    meson
-    ninja
-    pkg-config
-  ];
-
-  meta = with lib; {
-    description = "Rust app";
-    mainProgram = "app";
-    platforms = platforms.unix;
-  };
-}

templates/rust-app/flake.nix

@@ -1,42 +1,20 @@
 {
-  inputs = {
-    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
-    rust-overlay.url = "github:oxalica/rust-overlay";
-  };
+  description = "Basic Rust app development flake";
 
-  outputs = { self, nixpkgs, ... }@inputs:
+  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+
+  outputs = { nixpkgs, ... }:
     let
       inherit (nixpkgs) lib;
       systems = [ "x86_64-linux" ];
       forAllSystems = f: lib.genAttrs systems (system: f system);
-    in
-    {
-      devShells = forAllSystems
-        (system:
-          let
-            pkgs = import nixpkgs {
-              inherit system;
-              overlays = [
-                inputs.rust-overlay.overlays.default
-              ];
-            };
-          in
-          {
-            default = import ./shell.nix { inherit pkgs; };
-          });
+    in {
+      devShells = forAllSystems (system:
+        let pkgs = import nixpkgs { inherit system; };
+        in { default = import ./nix/shell.nix { inherit pkgs; }; });
 
-      packages = forAllSystems
-        (system:
-          let
-            pkgs = import nixpkgs {
-              inherit system;
-              overlays = [
-                inputs.rust-overlay.overlays.default
-              ];
-            };
-          in
-          {
-            default = pkgs.callPackage ./. { };
-          });
+      packages = forAllSystems (system:
+        let pkgs = import nixpkgs { inherit system; };
+        in { default = pkgs.callPackage ./nix/package.nix { }; });
     };
 }

templates/rust-app/nix/default.nix

@@ -0,0 +1,3 @@
+{ pkgs ? import <nixpkgs> { } }:
+
+pkgs.callPackage ./package.nix { }

templates/rust-app/nix/package.nix

@@ -0,0 +1,23 @@
+{ lib, stdenv, rustPlatform, cargo, rustc, meson, ninja, pkg-config }:
+
+let metadata = lib.importTOML ../Cargo.toml;
+in stdenv.mkDerivation (finalAttrs: {
+  pname = metadata.package.name;
+  version = metadata.package.version;
+
+  src = lib.fileset.toSource {
+    root = ../.;
+    fileset =
+      lib.fileset.unions [ ../Cargo.lock ../Cargo.toml ../src ../meson.build ];
+  };
+
+  nativeBuildInputs =
+    [ meson ninja pkg-config rustPlatform.cargoSetupHook cargo rustc ];
+
+  meta = with lib; {
+    description = metadata.package.description;
+    mainProgram = metadata.package.name;
+    platforms = platforms.unix;
+    license = with licenses; [ ];
+  };
+})

templates/rust-app/nix/shell.nix

@@ -0,0 +1,18 @@
+{ pkgs ? import <nixpkgs> { } }:
+
+let app = pkgs.callPackage ./package.nix { };
+in pkgs.mkShell {
+  inputsFrom = [ app ];
+
+  # The rest of the development-related packages should be here.
+  packages = with pkgs; [
+    direnv
+    clippy
+    rust-analyzer
+
+    # The formatters used in this project.
+    treefmt # The universal formatter (if configured nicely).
+    nixfmt # The universal Nix formatter.
+    rustfmt # The universal Rust formatter.
+  ];
+}