Comment 19 for bug 1867502

For those not using preseed, the above trick is also working. They just have to open a command line from the installer before updates (did it just before the network detection) and apply the sed command:

sed -i -e '/Package:
libc6-udeb/{N;N;s/Version: 2.3.*/Version: 2.31-0ubuntu9.3/}'
/var/lib/dpkg/status

This will trick a system which has version 2.31 of libc6-udeb to believe it have 2.31-0ubuntu9.3 (more up to date than the broken online version), thus not updating it.

They you just exit from the command line and proceed with the installation as usual.