Comment 3 for bug 1516014

Checked with "grub-probe -v" today and got:

grub-probe: info: /dev/sda is a parent of /dev/sda.
grub-probe: info: opening hd0.
grub-probe: info: drive = 0.
grub-probe: info: the size of hd0 is 125045424.
grub-probe: error: unknown filesystem.

Changed type from ext4 to ext2 and grub-update works again. Looks like ext4-support for /boot has been stripped from grub-update (at least for trusty with 32 bit, my trusty machine with 64 bit does not have this problem, both have version 2.02~beta2-9ubuntu1.4)