Bug#932127: grub-common: Fails loading snapshot after snapper rollback

[Steve McIntyre]

On Mon, Jul 15, 2019 at 04:58:06PM +0200, Thomas Schneider wrote:
>Package: grub-common
>Version: 2.04-1
>Severity: important
>
>-- Detailed issue description
>After finalizing Debian installation I installed additional packages to make
>usage of Btrfs' snapshot functionality:
>- btrfs-progs
>- snapper
>
>Then I started installation of package "reportbug":
>apt install reportbug
>
>Snapper automatically created a snapshot pre and post the installation. This
>is exactly what is expected.
>
>Then I initiated rollback of this installation:
>snapper rollback 3
>(where 3 represents the snapshot ID of the pre snapshot).
>
>This created another 2 snapshots with ID 5 and 6; snapshot 6 becomes the new
>default snapshot then.
>To verify the new default snapshot I use this syntax: btrfs su get-default /
>and this correctly returns this:
>ID 272 gen 3658 top level 261 patch @snapshots/6/snapshot
>
>This is the time to reboot the system.
>
>However, when system is back from reboot the package "reportbug" is still
>installed; I verified this simply by entering this: apt-cache policy r
>eportbug
>
>Please check attached screenshots documenting these steps and the current
>Grub menu commands.

Hi Thomas,

Could you please explain why you think this is a problem in the Grub
packages? You've created a snapshot, but not configured Grub to use
it. If snapper is meant to make this work automatically, then it
sounds like there is missing functionality in snapper?

-- 
Steve McIntyre, Cambridge, UK.                                steve at einval.com
Into the distance, a ribbon of black
Stretched to the point of no turning back