sys-boot/grub-9999 is no longer able to detect the filesystem with grub-probe, which means grub-install no longer works either. Reproducible: Always Steps to Reproduce: 1. emerge grub 2. grub-install /dev/md0 Actual Results: /usr/sbin/grub-probe: error: unknown filesystem. Auto-detection of a filesystem module failed. Please specify the module with the option `--modules' explicitly. Expected Results: Successful grub installation This is the commit that broke things for me : 2010-01-27 Vladimir Serbinenko <phcoder@gmail.com> * kern/disk.c (grub_disk_read): Fix offset computation when reading last sectors.
Please, report this issue upstream. Still reassigning on maintainers so they be aware about this issue and resolve it as they deem necessary.
I did not see an easy way to submit bugs upstream, but it seems they have already fixed the issue starting with EBZR_REVISION=2152