Create flake.nix for CLI

.github/workflows/nix-flake.yml

@@ -0,0 +1,33 @@
+name: Test Nix flake
+
+on:
+  push:
+    branches: [main]
+  # Only run for pull requests when the flake, toolchain, or action is modified.
+  pull_request:
+    paths:
+      - flake.nix
+      - flake.lock
+      - rust-toolchain.toml
+      - .github/workflows/nix-flake.yml
+  workflow_dispatch:
+
+jobs:
+  test-flake:
+    name: Test Nix flake
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v6
+
+      - name: Install Nix
+        uses: DeterminateSystems/determinate-nix-action@v3.15.2
+
+      - name: Check flake
+        run: nix flake check --all-systems
+
+      - name: Run Bevy CLI
+        run: nix run . -- --version
+
+      - name: Format `flake.nix`
+        run: nix-shell -p nixfmt --run "nixfmt --check --strict --verify flake.nix"

.gitignore

@@ -21,3 +21,7 @@ docs/book/
 
 # Internal Compiler Error files, generated when the linter panics.
 rustc-ice-*.txt
+
+# Generated by Nix flake
+result
+

README.md

@@ -51,6 +51,29 @@ If you want to try out the newest unstable features, you may install the CLI fro
 cargo install --git https://github.com/TheBevyFlock/bevy_cli --branch main --locked bevy_cli
 ```
 
+### Nix
+
+> Please note that Nix support is maintained on a best-effort basis, and therefore should not be considered stable. Features may be unavailable or break altogether as a result of future changes.
+
+The CLI is available to [Nix](https://nixos.org/) users as a [flake](https://wiki.nixos.org/wiki/Flakes). Simply add it as an input to your project's `flake.nix` to include it in the environment:
+
+```nix
+{
+  description = "A Bevy project flake.";
+
+  inputs = {
+    # Other inputs...
+    bevy_cli.url = "github:TheBevyFlock/bevy_cli";
+  };
+
+  outputs = { self, bevy_cli }: {
+    # Your outputs...
+  };
+}
+```
+
+An [example](https://github.com/bevyengine/bevy/blob/v0.18.0/docs/linux_dependencies.md#flakenix) project flake can be found in the official Bevy docs.
+
 ## Quick Start
 
 <!-- Please keep this section synchronized with the `mdbook` docs. -->

docs/src/cli/install.md

@@ -38,3 +38,26 @@ If you want to try out the newest unstable features, you may install the CLI fro
 ```sh
 cargo install --git https://github.com/TheBevyFlock/bevy_cli --branch main --locked bevy_cli
 ```
+
+## Nix
+
+> Please note that Nix support is maintained on a best-effort basis, and therefore should not be considered stable. Features may be unavailable or break altogether as a result of future changes.
+
+The CLI is available to [Nix](https://nixos.org/) users as a [flake](https://wiki.nixos.org/wiki/Flakes). Simply add it as an input to your project's `flake.nix` to include it in the environment:
+
+```nix
+{
+  description = "A Bevy project flake.";
+
+  inputs = {
+    # Other inputs...
+    bevy_cli.url = "github:TheBevyFlock/bevy_cli";
+  };
+
+  outputs = { self, bevy_cli }: {
+    # Your outputs...
+  };
+}
+```
+
+An [example](https://github.com/bevyengine/bevy/blob/v0.18.0/docs/linux_dependencies.md#flakenix) project flake can be found in the official Bevy docs.

flake.nix

@@ -0,0 +1,54 @@
+{
+  description = "A Bevy CLI tool and linter";
+
+  inputs = {
+    flake-utils.url = "github:numtide/flake-utils";
+    nixpkgs.url = "github:nixos/nixpkgs?ref=nixos-unstable";
+    rust-overlay = {
+      url = "github:oxalica/rust-overlay";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
+  };
+
+  outputs =
+    {
+      self,
+      flake-utils,
+      nixpkgs,
+      rust-overlay,
+    }:
+    flake-utils.lib.eachDefaultSystem (
+      system:
+      let
+        pkgs = nixpkgs.legacyPackages.${system}.extend rust-overlay.overlays.default;
+
+        nativeBuildInputs = with pkgs; [ pkg-config ];
+
+        buildInputs = with pkgs; [ openssl ];
+
+        toolchain = pkgs.rust-bin.fromRustupToolchainFile ./rust-toolchain.toml;
+
+        rustPlatform = pkgs.makeRustPlatform {
+          cargo = toolchain;
+          rustc = toolchain;
+        };
+      in
+      {
+        packages = {
+          default = self.outputs.packages.${system}.bevy;
+          bevy = rustPlatform.buildRustPackage {
+            pname = "bevy";
+            version = "0.1.0-dev";
+            src = ./.;
+            cargoLock.lockFile = ./Cargo.lock;
+            doCheck = false;
+
+            nativeBuildInputs = nativeBuildInputs ++ (with pkgs; [ makeBinaryWrapper ]);
+            inherit buildInputs;
+          };
+        };
+
+        devShells.default = pkgs.mkShell { inherit buildInputs nativeBuildInputs; };
+      }
+    );
+}