Mac Mini Photos library repair stuck at 99

Mac Mini 2024, just updated to 26.4. Can't open Photos, so I went to repair library (which is on an external hard drive, that has 235 GB free space and connected through the firewire port in the back). Repair screen went rapidly to 99% complete, it has now been sitting there for a few hours, the photos app is showing as "not responding" in the force quit menu. Safe to force quit?

I do have iCloud storage for the photos, also have my photos app on iPone and iPad, both just updated to 26.4, and those work fine.