anchor.diff:  
     smartdConf = pkgs.writeText "smartd.conf" (concatMapStrings (device:
       ''
  -      ${device} -a -m root -M exec ${smartdMail} ${cfg.deviceOpts}
  +      ${device.device} -a -m root -M exec ${smartdMail} ${device.options} ${cfg.deviceOpts}
       ''
       ) cfg.devices);
   
  
positive.code: 
        devices = mkOption {
          default = [];
          example = ["/dev/sda" "/dev/sdb"];
          description = ''
            List of devices to monitor. By default -- if this list is empty --,
            smartd will monitor all devices connected to the machine at the time
  
negative.code: let
  
    cfg = config.services.smartd;
  
    smartdOpts = { name, ... }: {
  
      options = {
  
        device = mkOption {
          example = "/dev/sda";
          type = types.string;
          description = "Location of the device.";
        };
  
        options = mkOption {
          default = "";
          example = "-d sat";
          type = types.string;
          merge = pkgs.lib.concatStringsSep " ";
          description = "Options that determine how smartd monitors the device";
        };
      };
  
    };
  
    smartdMail = pkgs.writeScript "smartdmail.sh" ''
      #! ${pkgs.stdenv.shell}
  