I did a fresh install on the exact same system (the notebook) and diffed both grub.cfg .
If I replace the grub.cfg from the failed upgrade by the one from the fresh install then it boots fine. So this looks like something with the way grub.cfg is generated during the upgrade.
Here are the 2 .cfg generated during upgrade and install.
I did a fresh install on the exact same system (the notebook) and diffed both grub.cfg .
If I replace the grub.cfg from the failed upgrade by the one from the fresh install then it boots fine. So this looks like something with the way grub.cfg is generated during the upgrade.
Here are the 2 .cfg generated during upgrade and install.