Comment 3 for bug 1955859

Thanks for your bug report. I believe you meant ubuntu-base, not ubuntu-core (the snap based one)

How did you test this? This seems to me like you forgot to populate /dev, either statically or by bind mounting the /dev from the host.

The tarball only contains an empty /dev, and the permissions have not changed.

jak@jak-t480s:~/Downloads$ tar tvzf jammy-base-amd64.tar.gz dev
drwxr-xr-x root/root 0 2021-12-28 06:01 dev/
jak@jak-t480s:~/Downloads$ tar tvzf focal-base-amd64.tar.gz dev
drwxr-xr-x root/root 0 2021-12-28 05:44 dev/

If APT had succeeded *creating* /dev/null as a regular files, all hell would have broken lose, so I am kind of happy that did not happen.

For the record, the reason it fails with EPERM seems to be that it's apt-key that's failing and it's run as the user _apt by apt.