Comment # 8 on bug 1160038 from Karl Mistelberger

(In reply to Michael Chang from comment #7)
> The grub.cfg looks no problem. Would you please help to provide grub runtime
> check via typing 'c' to enter grub command mode and gather these command
> output ?
>  
>  grub> ls /.snapshots
>  grub> btrfs-mount-subvol ($root) /.snapshots @/.snapshots
>  grub> ls /.snapshots
> 
> Thanks in advance.

btrfs-mount-subvol fails with: file /.snapshots not found.