Grub should define LANG=C in /etc/default/grub
Due to alpine using LANG=C.UTF-8
, this check in /etc/grub.d/00_header
if [ "x${LANG}" != "xC" ] && [ "x${LANG}" != "x" ]; then
(https://git.savannah.gnu.org/cgit/grub.git/tree/util/grub.d/00_header.in#n194)
gets confused and tries to load locale file C.gmo leading to error message during boot
error: file /boot/grub/locale/C.gmo not found
Can be solved by putting
LANG=C
into /etc/default/grub
.