I have a bunch of history commands I run when I d a new kernel etc and one stopped working.
grub-mkconfig would fail with grub-probe for /.
I read about a simialr issue where you where supposed to have a link for /dev/root to your root device and that fixed it right up.
grub-probe fails and I don't have /dev/root set
StudyPC /usr/src/linux # grub-probe /
grub-probe: error: cannot find a device for / (is /dev mounted?).
StudyPC /usr/src/linux # ls -l /dev/root
ls: cannot access '/dev/root': No such file or directory
Mount shows / is there and on sda2
StudyPC /usr/src/linux # mount
/dev/sda2 on / type btrfs (rw,noatime,ssd,discard,noacl,space_cache,subvolid=5,subvol=/)
..
waffle
..
So symlink that and try grub-mkconfig again
StudyPC /usr/src/linux # ln -s /dev/sda2 /dev/root
StudyPC /usr/src/linux # ls -l /dev/root
lrwxrwxrwx 1 root root 9 Mar 19 13:04 /dev/root -> /dev/sda2
StudyPC /usr/src/linux # grub-probe
No path or device is specified.
Usage: grub-probe [OPTION...] [OPTION]... [PATH|DEVICE]
Try 'grub-probe --help' or 'grub-probe --usage' for more information.
StudyPC /usr/src/linux # grub-probe /
btrfs
And we're good! No more handcoding grub.cfg
