Bug#1080056: systemd-timesyncd: system clock goes out of sync, despite service being enabled and active

[Luca Boccassi]

Control: close -1

On Fri, 30 Aug 2024 09:05:31 +0200 Ralf Jung <post at ralfj.de> wrote:
> Package: systemd-timesyncd
> Version: 256.4-3
> Severity: normal
> 
> Dear Maintainer,
> 
> some time ago, syncing my Laptop clock seems to have stopped working.
I can tell
> how it slowly drifts away from other, radio-controlled clocks in my
apartment.
> 
> This is despite systemd-timesync being set up for automatic
synchronization:
> 
> $ timedatectl 
>                Local time: Fr 2024-08-30 08:58:25 CEST
>            Universal time: Fr 2024-08-30 06:58:25 UTC
>                  RTC time: Fr 2024-08-30 06:58:25
>                 Time zone: Europe/Zurich (CEST, +0200)
> System clock synchronized: no
>               NTP service: active
>           RTC in local TZ: no
> 
> $ systemctl status systemd-timesyncd.service 
> ● systemd-timesyncd.service - Network Time Synchronization
>      Loaded: loaded (/usr/lib/systemd/system/systemd-
timesyncd.service; enabled; preset: enabled)
>      Active: active (running) since Sun 2024-08-18 08:34:18 CEST; 1
week 5 days ago
>  Invocation: 7bd1c1b03524445c8d9e2e6fcb5bb1ba
>        Docs: man:systemd-timesyncd.service(8)
>    Main PID: 978 (systemd-timesyn)
>      Status: "Idle."
>       Tasks: 2 (limit: 38086)
>      Memory: 1.1M (peak: 3.4M swap: 824K swap peak: 944K)
>         CPU: 3.364s
>      CGroup: /system.slice/systemd-timesyncd.service
>              └─978 /usr/lib/systemd/systemd-timesyncd
> 
> Manually restarting systemd-timesyncd.service seems to trigger a
sync.
> 
> $ sudo systemctl restart systemd-timesyncd.service
> $ timedatectl 
>                Local time: Fr 2024-08-30 08:59:19 CEST
>            Universal time: Fr 2024-08-30 06:59:19 UTC
>                  RTC time: Fr 2024-08-30 06:59:19
>                 Time zone: Europe/Zurich (CEST, +0200)
> System clock synchronized: yes
>               NTP service: active
>           RTC in local TZ: no
> 
> Note how "System clock synchronized" switched to "yes". Manual
comparison with a
> radio-controlled clock also confirms that they are in sync now. But
obviously, I
> shouldn't have to manually restart this service to get it to
synchronize the
> clock.
> 
> Unfortunately I have no idea how to even debug this.
> 
> Kind regards,
> Ralf

There are no timesyncd patches or custom configurations in Debian, so
please file this issue upstream with the appropriate debug logs and
reproducers.