{
  description = "A very basic flake";

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

  outputs = { self, nixpkgs, utils }:
    utils.lib.eachDefaultSystem (system:
      let
        pkgs = nixpkgs.legacyPackages.${system};
        llvmPkgs = pkgs.llvmPackages_12;
        myPkgs = rec { e0 = pkgs.callPackage ./. { inherit llvmPkgs; }; };

      in rec {
        devShell = pkgs.mkShell {
          packages = with pkgs; [ llvmPkgs.clangUseLLVM cargo-watch ];
          inputsFrom = [ myPkgs.e0 ];
        };

        packages = utils.lib.flattenTree myPkgs;
        defaultPackage = packages.e0;
      });
}