{
  inputs = { fenix.url = "github:nix-community/fenix"; };

  outputs = { self, nixpkgs, flake-utils, fenix }:
    flake-utils.lib.eachDefaultSystem (system:
      let
        pkgs = import nixpkgs {
          inherit system;
          overlays = [ fenix.overlays.default ];
        };

        toolchain = pkgs.fenix.stable;

        flakePkgs = {
          #   mzci = pkgs.callPackage ./. { inherit toolchain; }; 
        };
      in rec {
        packages = flake-utils.lib.flattenTree flakePkgs;
        # defaultPackage = packages.mzci;

        devShell = pkgs.mkShell {
          inputsFrom = with packages;
            [ # mzci
            ];
          packages = (with pkgs; [ cargo-watch cargo-deny cargo-edit ])
            ++ (with toolchain; [
              cargo
              rustc
              rustfmt

              # Get the nightly version of rustfmt so we can wrap comments
              pkgs.fenix.default.rustfmt
            ]);
          CARGO_UNSTABLE_SPARSE_REGISTRY = "true";
        };
      });
}