re-enable grub automated upgrades?
i wonder if this issue might have actually been fixed in Debian's grub scripts... I am not sure what error we were getting on the console here exactly, but if i remember correctly, it looked something like bug 966575 in the Debian BTS, which is:
GRUB loading. Welcome to GRUB! error: symbol 'grub_calloc' not found. grub rescue>
was that the exact error?
if that's the case, then the bug above is marked as fixed in grub 2.02+dfsg1-20+deb10u3, which has been shipped everywhere. also, since that version, grub-pc upgrades will completely fail if
grub-install fails, which should at least mark the package as broken in situations such as this.
so should we remove this from the unattended-upgrades blocklist?