Hi! We have recently backported the upstream changes to Debian's grub2 package to support modern SPARC hardware for Debian's sparc64 port.
One of the changes introduced a regression on systems with NVME devices which are not based on Open Firmware. On these systems, find_obppath returns an empty string and trying to append the disk name to that empty name results in a crash in of_path_of_nvme. Fix that by making sure of_path isn't empty and if it is, just return the disk name in of_path_of_nvme. Debian bug: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=891773 Thanks, Adrian