{
  description = "A very basic flake";

  inputs = {
    nixpkgs.url = "github:nixos/nixpkgs?ref=nixos-unstable";
  };

  outputs = {
    self,
    nixpkgs,
  }: let
    pkgs = import nixpkgs {system = "x86_64-linux";};
    cl-dates = pkgs.sbcl.buildASDFSystem {
      pname = "cl-dates";
      version = "latest";
      src = ./.;
    };
  in {
    packages.x86_64-linux.default = cl-dates;

    devShells.x86_64-linux.default = pkgs.mkShell {
      buildInputs = [
        (pkgs.sbcl.withPackages (ps: [
          cl-dates
        ]))
      ];
    };
  };
}