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by Arnavion 1395 days ago
The issue is that it's not possible to create wakeup timers without root or CAP_WAKE_ALARM, hence why you need a more privileged daemon of some sort that your regular alarm clock app binary. Eg with systemd it doesn't let timer units in the user session that can wake the system, which is what is blocking gnome-clocks upstream from using systemd timer units.

But yes, I don't know why waked uses the dev node directly instead of using CLOCK_ALARM, and it's definitely possible it interferes with anything else going through the kernel using CLOCK_ALARM.
1 comments
megous 1395 days ago
Maybe I'm missing something, but why not simply `setcap cap_wake_alarm+p gnome-clocks` and any other app that may legitimately use this?
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Arnavion 1395 days ago
No, you're not missing anything. I should've been clearer that I was talking about gnome-clocks specifically, which wants to use systemd both so that only systemd needs the privileges rather than gnome-clocks itself and so that it can autostart gnome-clocks using the timer [1] even if gnome-clocks is down at the time (ie gnome-clocks doesn't itself need to keep the timerfd alive).

In general, setcap'ing the binary will work fine.

[1]: https://gitlab.gnome.org/GNOME/gnome-clocks/-/merge_requests...

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