Boot method: DVD
Image version: debian-13.0.0-amd64-DVD-1.iso (customized)
Date: 2025-08-10

Machine: Hyper-V / VirtualBox VM

Not sure whether this is classified as a Debian Installer or apt problem:

I've been creating a customized installation ISO image with a preseed file
for several versions.

My configuration was working fine until Trixie, i.e. it works in <=Bookworm.

I copy a custom sources.list during installation with a late_command:

The sources.list obviously doesn't contain the cdrom entries.

This breaks on Trixie, on step "Finish the installation", it will start
prompting for an install media in a loop:

According to console output, this is caused by
/usr/lib/finish-install.d/08hw-detect:

The virtualization packages (e.g. hyperv-daemons, virtualbox-guest-utils)
are not even available on (at least) the DVD1 media?

Also, it should be able to find & mount my DVD by label too, because I
configure it into $MEDIA/.disk/info (the error message displays the correct
custom label for the media)

So, both errors appear to be irrelevant.

Regardless, as a workaround, I added a preseed early_command:

This fixes the preseed installation.

However, this results in virtualization tools and processor microcode
packages not installing.