Package: os-prober Version: 1.71 With os-prober installed and then running update-grub and grub-install all I know is after rebooting I couldn't use any USB stuff after Debian started the main boot choice. As I depend on a USB keyboard, the only way to regain control of my computer again was to hit the power button, and upon reboot quickly pick recovery mode from the grub menu. If I just instead sit there my computer starts X windows and the only way out is the power button. No I don't know why but it must have to do with those eerie kernel messages you see,
Anyway I have now "aptitude purge"d os-prober and ran update-grub and grub-install and now my computer is working again! Yes there are a few less boot menu choices but it is worth it.