Comment 5 for bug 2031253

I tried just commenting out the section of subiquity/server/apt.py:

        write_file(
            self.install_tree.p("etc/apt/sources.list"),
            f"deb [check-date=no] file:///cdrom {codename} main restricted\n",
        )

And recreating the subiquity snap to patch it into the ISO so that I could see if this was actually the root of the problem. Sadly I was unable to install the snapcraft snap on my 23.04 system, it gives an error about python3 not being found even though it is available. I was able to get snapcraft installed on a 20.04 system and from there I was able to modify and build subiquity, but when I run the scripts/inject-subiquity-snap.sh script, the ISO that it produces is not net-bootable. I can boot it manually but from there I have no ability to trigger the cloud-init, I just get the graphical interactive setup. I could probably modify the grub.cfg in the ISO, but it is late and I've been at this all day.

Hopefully some Canonical developers with better understanding of the ISO creation and testing workflows can come along and take a look at this.