"The selected photo library is currently in the process of disabling iCloud Photos. Please try again later."

I'm trying to merge two photo libraries and I've been getting this error for the past 24 hours. The selected photo library is >not< my system library and is >not< syncing with icloud photos...

Any ideas? I've tried repairing the source library, didn't help.

I'm running Ventura and Photos version 8.0. I'd really rather not export all the photos from the old library because it would lose all the relationships between raw and jpgs, edit history, etc..