".. since it was using a systemd timer unit, that error output went to the journal and was effectively invisible to us, lost within a flood of messages". One a side note - the comments section of the article contains an example of why some people are just so toxic these days
From xxx at 2019-11-05 12:25:37:
dozzie: It doesn't require knowing systemd inside and out because it is on the Arch Wiki. You are just bad.