{
  inputs = {
    nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
    flake-utils.url = "github:numtide/flake-utils";
    rust-overlay.url = "github:oxalica/rust-overlay";
  };

  outputs = { self, nixpkgs, flake-utils, rust-overlay, ... }:
    flake-utils.lib.eachDefaultSystem (system:
      let
        overlays = [ (import rust-overlay) ];
        pkgs = import nixpkgs { inherit system overlays; };
        rustVersion = pkgs.rust-bin.stable.latest.default;
        rustPlatform = pkgs.makeRustPlatform {
          cargo = rustVersion;
          rustc = rustVersion;
        };
        myRustBuild = rustPlatform.buildRustPackage {
          pname = "tmpmail";
          version = "0.1.0";
          src = ./.;
          cargoLock.lockFile = ./Cargo.lock;
        };
      in {
        defaultPackage = myRustBuild;
        devShell = pkgs.mkShell {
          buildInputs =
            [ (rustVersion.override { extensions = [ "rust-src" ]; }) ];
        };
      }
    ) // {
    nixosModules.default = { config, lib, pkgs, ... }:
      with lib;
      let cfg = config.mawalu.services.norbert;
      in
        {
          options.mawalu.services.rail = {
            enable = mkEnableOption "Enable the rail tmpmail server";
          };

          config = mkIf cfg.enable {
            systemd.services.rail = {
              wantedBy = [ "multi-user.target" ];

              serviceConfig = let pkg = self.packages.${pkgs.system}.default;
              in {
                Restart = "on-failure";
                ExecStart = "${pkg}/bin/tmpmail";
                DynamicUser = "yes";
                AmbientCapabilities = ["CAP_NET_BIND_SERVICE"];
              };
            };
          };
        };
  };
}