anchor.diff:            <filename><replaceable>pkg</replaceable>/etc/udev/rules.d</filename> and
             <filename><replaceable>pkg</replaceable>/lib/udev/rules.d</filename>
             will be included.
  +        '';
  +      };
  +
  +      path = mkOption {
  +        default = [];
  +        merge = mergeListOption;
  +        description = ''
  +          Packages added to the <envar>PATH</envar> environment variable when
  +          executing programs from Udev rules.
           '';
         };
   
  
positive.code:       cp -v ${udev}/libexec/rules.d/*.rules $out/
  
        # Set a reasonable $PATH for programs called by udev rules.
        echo 'ENV{PATH}="${pkgs.coreutils}/bin:${pkgs.gnused}/bin:${pkgs.utillinux}/bin"' > $out/00-path.rules
  
        # Set the firmware search path so that the firmware.sh helper
        # called by 50-firmware.rules works properly.
  
negative.code:     #udev_log="debug"
    '';
  
    # Udev has a 512-character limit for ENV{PATH}, so create a symlink
    # tree to work around this.
    udevPath = pkgs.buildEnv {
      name = "udev-path";
      paths = cfg.path;
      pathsToLink = [ "/bin" "/sbin" ];
      ignoreCollisions = true;
    };
  
  in
  
  {
  