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

  outputs = { self, nixpkgs, flake-utils }:
    flake-utils.lib.eachDefaultSystem (system:
      let pkgs = nixpkgs.legacyPackages.${system};
      in with pkgs; {
        devShells.default = mkShell {
          buildInputs = [
            (lua5_3.withPackages (ps:
              with ps; [
                (buildLuarocksPackage {
                  pname = "cmark";
                  version = "0.30.2-1";
                  knownRockspec = (fetchurl {
                    url = "mirror://luarocks/cmark-0.30.2-1.rockspec";
                    sha256 =
                      "077kvl9xa9yj0fxyyxxw43k9v9dgd5f11ax8hhxj3nx8vfs5rps8";
                  }).outPath;

                  src = fetchFromGitHub {
                    owner = "jgm";
                    repo = "cmark-lua";
                    rev = "0.30.2";
                    hash =
                      "sha256-6Bzq0FdyqXXiL6pLDRFbULFJpowF0P6CvAw8iqFXkkQ=";
                  };
                })
                luafilesystem
                luasocket
                luasec
                fennel
              ]))
          ];
        };
      });
}