Comment 27 for bug 1848797

Update: not related to proprietary drivers (cannot delete/update my own 2 previous posts), even with those deinstalled, the upgrade will fail.

Have an old VM 19.04 from May: after updating this system & then upgrading to 19.10, it will reliably destroy grub. Let me know if you need support to debug this, I'm reliably able to reproduce it.