{
  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
    fenix.url = "github:nix-community/fenix";
    fenix.inputs.nixpkgs.follows = "nixpkgs";
  };

  outputs =
    { nixpkgs, fenix, ... }:
    let
      forAllSystems =
        function:
        nixpkgs.lib.genAttrs [
          "aarch64-darwin"
        ] (system: function nixpkgs.legacyPackages.${system});
    in
    {
      devShells = forAllSystems (pkgs: {
        default = pkgs.mkShell {
          packages = [
            fenix.packages.${pkgs.system}.stable.toolchain
            pkgs.capnproto
          ];
        };
      });
    };
}