{
  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable-small";
  };

  outputs = {
    self,
    nixpkgs,
    ...
  }: let
    system = "x86_64-linux";
    pkgs = nixpkgs.outputs.legacyPackages.${system};

    turtle = pkgs.callPackage ./nix/package.nix {};
    tests = let
      test-turtle = turtle.overrideAttrs {
        cargoBuildType = "debug";
      };
    in
      pkgs.testers.runNixOSTest {
        imports = [./tests/basic.nix];
        defaults = {
          services.turtle.package = test-turtle;
          environment.systemPackages = [
            test-turtle
          ];
        };
      };

    module = import ./nix/module.nix {extraPackages = {inherit turtle;};};
  in {
    packages."${system}" = {
      inherit turtle;
      default = self.outputs.packages.${system}.turtle;
    };
    nixosModules.default = module;

    checks."${system}".default = tests;

    devShells."${system}".default = self.packages.${system}.default.overrideAttrs (super: {
      nativeBuildInputs =
        super.nativeBuildInputs
        ++ [
          # rust stuff
          pkgs.cargo
          pkgs.clippy
          pkgs.rustc
          pkgs.rustfmt
          pkgs.mold

          pkgs.cargo-edit
          pkgs.cargo-expand
          pkgs.cargo-flamegraph
        ];
      RUST_SRC_PATH = "${pkgs.rustPlatform.rustLibSrc}";
    });
  };
}