anchor.diff:          description = "timer for ACME cert renewal of ${cert}";
           wantedBy = [ "timers.target" ];
           timerConfig = {
  -          OnCalendar = data.renewInterval;
  +          OnCalendar = cfg.renewInterval;
             Unit = "acme-simp_le-${cert}.service";
           };
         })
  
positive.code:         '';
        };
  
        certs = mkOption {
          default = { };
          type = types.loaOf types.optionSet;
  
negative.code:           will be created automatically if it doesn't exist.
            <literal>http://example.org/.well-known/acme-challenge/</literal> must also
            be available (notice unencrypted HTTP).
          '';
        };
  
  