snapper: Boot failed after installation

Reported here: https://discuss.freedombox.org/t/feedback-about-freedombox-setup-in-a-bullseye-rc3-fresh-install/1718

Incorrect btrfs option in fstab caused the boot sequence to halt

Summary

The automatic FreedomBox installer used subvol=.snapshot to identify the subvolume, but that didn’t work.

Description

UUID=44539a99-4cf0-456b-b4ec-5e94139e8f63 /.snapshots btrfs subvol=.snapshots 0 1

Proposed Solution

Using the subvolid seemed to work: UUID=44539a99-4cf0-456b-b4ec-5e94139e8f63 /.snapshots btrfs subvolid=260 0 1