anchor.diff:  with lib;
   
   let
  +  cfg = config.nixpkgs;
  +
     isConfig = x:
       builtins.isAttrs x || builtins.isFunction x;
   
  
positive.code:     merge = lib.mergeOneOption;
    };
  
    _pkgs = import ../../.. config.nixpkgs;
  
  in
  
  {
    options.nixpkgs = {
      config = mkOption {
        default = {};
        example = literalExample
  
negative.code:         If unset, it defaults to the platform type of your host system.
          Specifying this option is useful when doing distributed
          multi-platform deployment, or when building virtual machines.
  
          Ignored when <code>nixpkgs.pkgs</code> is set.
        '';
      };
    };
  
    config = {
      _module.args = {
        pkgs = cfg.pkgs;
        pkgs_i686 = cfg.pkgs.pkgsi686Linux;
      };
    };
  }
  