The grub-probe problem was pilot error; I forgot to run it as root. Sorry for the noise.
I've changed GRUB to add rootflags=subvol=<name> automatically where needed, and have uploaded partman-btrfs to fix subvolume permissions. Nearly there ...
The grub-probe problem was pilot error; I forgot to run it as root. Sorry for the noise.
I've changed GRUB to add rootflags= subvol= <name> automatically where needed, and have uploaded partman-btrfs to fix subvolume permissions. Nearly there ...