{
  inputs = {
    cargo2nix.url = "github:cargo2nix/cargo2nix";
    nixpkgs.follows = "cargo2nix/nixpkgs";
    flake-utils.follows = "cargo2nix/flake-utils";
  };

  outputs = { self, nixpkgs, flake-utils, cargo2nix }:
    flake-utils.lib.eachDefaultSystem (system:
      let
        pkgs = import nixpkgs {
          inherit system;
          overlays = [ cargo2nix.overlays.default ];
        };

        rustPkgs = pkgs.rustBuilder.makePackageSet {
          rustVersion = "1.75.0";
          packageFun = import ./Cargo.nix;
        };

        workspaceShell = (rustPkgs.workspaceShell); # supports override & overrideAttrs
      in
      rec
      {
        packages = {
          mice-roll = (rustPkgs.workspace.mice-roll { });
          default = packages.mice-roll;
        };
        devShells = {
          # nix develop
          default = workspaceShell;
        };

      });
}