Comment 4 for bug 1424789

What message do you get in the initramfs?

Installation problems are rarely irrelevant when they precede a failure to boot; certainly some package has not yet been configured and that's why running 'sudo apt-get install luibuntu-desktop' fixes things.

If you see the same error messages in install as in the other bugs you linked, then it's indeed a problem that can be caused by the failing installation, especially if you're seeing these messages about libgl* failing to be installed (Conflicts).

I'll reassign this to pkgsel for now, but without the details from the installation (the exact messages that appeared, which may still be in /var/log/installer), it's going to be hard to resolve this after the fact.