Created attachment 349534 [details] ntp configure --help output There's a lot of hardware clock available for ntp at configure time with --enable-XXX Using a package variable like NTP_REFCLOCK to choose which one to enable could be a smart way to allow users to build their stratum 1 server with any ntp supported refclock (and building only support for this one) Furthermore, i had some needed configure options which were not supported by any USE flag in ntp-4.2.6_p5-r1 ebuild : * --with-net-snmp-config (could be added to snmp use flag) * --enable-clockctl