Sorry for responding late.
So running sailtrix from terminal only gives me this:
[defaultuser@JollaC2 ~]$ /usr/bin/harbour-sailtrix
[D] unknown:0 - Opening existing instance
[D] unknown:0 - Sending open signal
[defaultuser@jollaC2 ~]$
Basically I know how piping works, but where do I get logs from?
Could I get another hint here?
And another question that came up is:
Messages are all encrypted when I reopen Sailtrix.
Sometimes messages get encrypted even while the app is active. Being suddenly not able to read what was written before is pretty annoying.
Why is that? And can I do something about it?
Yes, at least research where its source code repository is and report issues with it there (or as a worse alternative, at OpenRepos in the comments).
This forum (FSO) is only suitable for reporting issues with software from Jolla, except for the few apps whose maintainers offer a support thread here at FSO (Patchmanager, µTube etc.); but even for these it is much better to use their original issue tracker (though less convenient for you).
“Piping” was a bit misleading here, unfortunately, the correct term is “output redirection” (that is, either to a file [handle] or another command): [defaultuser@JollaC2 ~]$ /usr/bin/harbour-sailtrix > ~/sailtrix_$(date +%F_%H-%M-%S).log.txt
This would have done the job, but will simply record what you saw on the screen (which does not appear to be relevant).
If you want to achieve both, seeing the output on the screen and record it in a file, do pipe (“really”, here) through tee (still as regular user, i.e. not root): harbour-sailtrix | tee ~/sailtrix_$(date +%F_%H-%M-%S).log.txt