Hello,
As reported on a side-note in #1110534, the GNOME live image for trixie
13.0.0 installs a nearly empty 'sources.list' file when using the live
d-i installer. The sources.list file only contains the CD-ROM entry and
no comments.
The installer does not ask for a mirror, while the 12.11 live image did so.
Looking at the syslog files in /var/log/installer for both installations
(with DEBCONF_DEBUG=5), it turns out that some udeb files are not
present on the live image, e.g. apt-mirror-setup.
Also noted in #1112485, some espeakup related packages are missing too.
So most probably the bug can be found in the step that builds the installer.
With kind regards,
Roland