Bug#966575: Security update can break grub - grub_calloc not found

[Geoff Gibbs]

apt update
apt full-upgrade

grub upgrades

from 2.02+dfsg1-20
to 2.02+dfsg1-20+deb10u1

no errors were spotted.

When rebooted :-

symbol grub_calloc not found
Entering rescue mode
grub rescue>


I had to boot off a memory stick and then :-

sudo -i
mount /dev/sda5 /mnt
grub-install --boot-directory=/mnt /dev/sda
reboot

This worked and the system now boots.

/boot is the only ext type file system, the others are all handled by LVM

Geoff