plasma-desktop should not rdepend on net-misc/ntp or net-misc/rdate because (1) Neither ntp nor rdate are actually required for any element of plasma-desktop to compile or run. They are used only by the date/time applet of the control panel. (2) The date/time applet of the control panel will detect if systemd's time sync service — or anything else that listens on "org.freedesktop.timedate1" thru DBUS — is running. (3a) If the date/time applet cannot detect an NTP client via dbus, it will check if ntpdate or rdate are installed. If they are not, the applet will display an error that is inaccurate, because … (3b) … there are several other NTP clients that the computer could be running that keep the time updated, but the applet doesn't check for any of them. To quote the commit that added systemd checking (https://cgit.kde.org/plasma-desktop.git/commit/kcms/dateandtime/dtime.cpp?id=b6ae01ca8ea776c97cc57836401ca9696e2529e8): "The current time setting helper is incredibly broken." So let's not exacerbate the problem by requiring installation of unnecessary software.
Do you use systemd?
I do and indeed ntp runtime dependency for systemd users is excessive so we should have it behind !systemd USE flag at least. Not sure I agree with Soren's idea to drop the dependency completely though, if anything, 3b) would be the rationale to conditionally (for non systemd users) patch out plasma functionality to control NTP at all.
On second thought, perhaps dropping rdep and optionally adding some elog message is the least restrictive option.
I run chrony on an openrc system. I can't see what use the t&d applet is at all if the system time is being maintained independently of any desktop environment. Certainly I've never used it in KDE-3, KDE-4 or plasma.
If the KDE codebase is designed specifically for one NTP implementation it makes sense to list it in the dependencies, perhaps behind a USE flag. The concerns given are valid but should probably be added to the KDE tracker.
I suggest just putting out an elog (if that is even necessary). I could see this being a dependency issue if it was a build-time issue. However, this sounds like purely a runtime issue. Plasma will offer to control the time server if one is installed, and if not it won't. I don't think this is unexpected behavior. Maybe in a future release the control panel will have the ability to start/stop systemd units over DBUS. That wouldn't be a reason to require a systemd or dbus dependency unless it changes how it is built (in which case USE flags would be appropriate). It is just optional functionality that the package enables at runtime if the system supports it. Numerous packages work this way.
Grayed out button has tooltip "No NTP utility has been found. Install 'ntpdate' or 'rdate' command to enable automatic updating of date and time." Therefore build-time message is not necessary. Rdep dropped. Thanks for reporting.
