Thank you. Looking at the commands again, they don’t look like something I could just cut, paste, and run.
Also I found this post, where people report trying various things in vain: Update of manjaro-keyring gave errors - #22 by shadowsofnoxus
I believe I will first roll back my Manjaro VM to the last snapshot and see whether that fixes anything.
Is there any command that will check the keyrings and produce a status report (e.g.what is wrong)?