anchor.diff:              bind = mkOption {
                 type = with types; nullOr str;
                 default = if name == "" then "127.0.0.1" else null;
  -              defaultText = "127.0.0.1 or null if name != \"\"";
  +              defaultText = literalExpression ''if name == "" then "127.0.0.1" else null'';
                 description = ''
                   The IP interface to bind to.
                   <literal>null</literal> means "all interfaces".
  
positive.code: 
              port = mkOption {
                type = types.port;
                default = 6379;
                description = "The port for Redis to listen to.";
              };
  
              openFirewall = mkOption {
  
negative.code:           };
            config.settings = mkMerge [
              {
                port = config.port;
                daemonize = false;
                supervised = "systemd";
                loglevel = config.logLevel;
  