Well. I moved SSDs between two boxes. I kept a HD behind (it only has rsync and backuppc stuff on it). The one that was to be my new Linux work PC, this one, came up fine.
The box with my #mastodon instance and a chat room on it decided it should boot to MacOS. And so it did.
Clover is still installed.
Where is the Linux boot partition?
Was another drive hiding?
I have mysteries to sort through. Meanwhile, my private instance is down.