Nix activation script

gistfile1.txt

let
  pkgs = import <nixpkgs> {};
  lib = pkgs.lib;
  addAttributeName = with lib; mapAttrs (a: v: v // {
    text = ''
      ${v.text}
    '';
  });
in
with lib;
(evalModules {
  modules = [
    {
      options.aS = mkOption {
        default = {};
        type = types.attrsOf types.unspecified;
        apply = set: {
        script =
          ''
            ${
              let
                set' = mapAttrs (n: v: if isString v then noDepEntry v else v) set;
                withHeadlines = addAttributeName set';
              in textClosureMap id (withHeadlines) (attrNames withHeadlines)
            }
          '';
        };
      };
    }

    # when this is before instead of after, it works
    # {
    #   aS.c = "c";
    #   aS.a.deps = [ "c" ];
    # }

    {
      aS.a = stringAfter ["b"] "a";
      aS.b = "b";
    }

    {
      aS.c = "c";
      aS.a.deps = mkOverride 0 [ "c" ];
    }


  ];
}).config.aS.script