feat(templates/bevy): add support for darwin, and use rust-analyzer-nightly for better type inference

templates/bevy/flake.nix

@@ -4,20 +4,22 @@
 
   inputs = {
     nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
-    rust-overlay = {
-      url = "github:oxalica/rust-overlay";
+    fenix = {
+      url = "github:nix-community/fenix";
       inputs.nixpkgs.follows = "nixpkgs";
     };
   };
 
   outputs = {
     nixpkgs,
-    rust-overlay,
+    fenix,
     ...
   }: let
     systems = [
       "x86_64-linux"
       "aarch64-linux"
+      "x86_64-darwin"
+      "aarch64-darwin"
     ];
     # Helper function to generate a set of attributes for each system
     forAllSystems = func: (nixpkgs.lib.genAttrs systems func);
@@ -25,29 +27,78 @@
     devShells = forAllSystems (system: let
       pkgs = import nixpkgs {
         inherit system;
-        overlays = [(import rust-overlay)];
+        overlays = [fenix.overlays.default];
       };
       lib = pkgs.lib;
     in {
       default = pkgs.mkShell rec {
         nativeBuildInputs = with pkgs; [
           pkg-config
+          clang
+          # lld is much faster at linking than the default Rust linker
+          lld
         ];
-        buildInputs = with pkgs; [
-          udev
-          alsa-lib
-          vulkan-loader
-          xorg.libX11
-          xorg.libXcursor
-          xorg.libXi
-          xorg.libXrandr # To use the x11 feature
-          libxkbcommon
-          wayland # To use the wayland feature
-
-          # rust toolchain
-          rust-analyzer
-        ];
+        buildInputs = with pkgs;
+          [
+            # rust toolchain
+            (pkgs.fenix.complete.withComponents [
+              "cargo"
+              "clippy"
+              "rust-src"
+              "rustc"
+              "rustfmt"
+            ])
+            rust-analyzer-nightly
+          ]
+          # https://github.com/bevyengine/bevy/blob/v0.14.2/docs/linux_dependencies.md#nix
+          ++ (lib.optionals pkgs.stdenv.isLinux [
+            udev
+            alsa-lib
+            vulkan-loader
+            xorg.libX11
+            xorg.libXcursor
+            xorg.libXi
+            xorg.libXrandr # To use the x11 feature
+            libxkbcommon
+            wayland # To use the wayland feature
+          ])
+          # https://discourse.nixos.org/t/develop-shell-environment-setup-for-macos/11399
+          # https://github.com/NixOS/nixpkgs/blob/nixos-unstable-small/pkgs/os-specific/darwin/apple-sdk/frameworks.nix
+          ++ (pkgs.lib.optionals pkgs.stdenv.isDarwin [
+            # Additional darwin specific inputs can be set here
+            libiconv
+            darwin.apple_sdk.frameworks.Security
+            darwin.apple_sdk.frameworks.ApplicationServices
+            darwin.apple_sdk.frameworks.CoreVideo
+            darwin.apple_sdk.frameworks.Carbon
+            darwin.apple_sdk.frameworks.AppKit
+          ]);
         LD_LIBRARY_PATH = lib.makeLibraryPath buildInputs;
+        COREAUDIO_SDK_PATH =
+          pkgs.lib.optionals
+          pkgs.stdenv.isDarwin
+          # The coreaudio-sys crate is configured to look for things in whatever the
+          # output of `xcrun --sdk macosx --show-sdk-path` is. However, this does not
+          # always contain the right frameworks, and it uses system versions instead of
+          # what we control via Nix. Instead of having to run a lot of extra scripts
+          # to set our systems up to build, we can just create a SDK directory with
+          # the same layout as the `MacOSX{version}.sdk` that XCode produces.
+          (pkgs.symlinkJoin {
+            name = "sdk";
+            paths = with pkgs.darwin.apple_sdk.frameworks; [
+              AudioToolbox
+              AudioUnit
+              CoreAudio
+              CoreAudioTypes
+              CoreFoundation
+              CoreMIDI
+              OpenAL
+            ];
+            postBuild = ''
+              mkdir $out/System
+              mv $out/Library $out/System
+            '';
+          });
       };
     });
   };