Bug#949209: installation-reports: grub install fails because efivarfs is not mounted on /target

[Julien <julien@peclu.net>]

Package: installation-reports

Dear Maintainer,


I've installed debian on my computer with the following partitions :

# / (partitionless btrfs ssd)
UUID=586da4fd-9a26-4350-8146-929dbdde3581 / btrfs defaults 0 0

# /boot/efi (fat partition on GPT ssd)
UUID=6A71-114F /boot/efi vfat umask=0077 0 1

# swap (swap partition on GPT ssd)
UUID=3f398aee-8e74-4b2e-b7a9-6b537d9bb414 none swap sw 0 0

# /home/julien (partitionless btrfs ssd)
UUID=3e47af4b-7d6d-4830-ac7b-16345771896f /home/j btrfs defaults 0 0

At the grub step, i've got a grub-install dummy failed error.

   * What exactly did you do (or not do) that was effective (or
ineffective)?

I've switched to the shell and executed the following commands :

# mount -t sys sys /target/sys
# mount -t efivarfs efivarfs /target/sys/firmware/efi/efivars
# chroot /target/ bash
# grub-install
# update-grub

And I've resumed the normal installation process.

Image version: 
https://cdimage.debian.org/cdimage/bullseye_di_alpha1/amd64/iso-cd/debian-bullseye-DI-alpha1-amd64-netinst.iso


Base System Installation Checklist:
[O] = OK, [E] = Error (please elaborate below), [ ] = didn't try it

Initial boot:           [O]
Detect network card:    [O]
Configure network:      [O]
Detect media:           [O]
Load installer modules: [O]
Clock/timezone setup:   [O]
User/password setup:    [O]
Detect hard drives:     [O]
Partition hard drives:  [O]
Install base system:    [O]
Install tasks:          [O]
Install boot loader:    [E]
Overall install:        [O]


Regards,
Julien