Shell version of grub-install called grub-setup which resolved
install device name and called main setup routine. C version of
grub-install calls main setup routine directly, which leads
to the error:
grub2-install: info: grub-bios-setup --verbose --force --skip-fs-probe --directory='/boot/grub2/i386-pc' --device-map='/boot/grub2/device.map' '(hd2)'.
grub2-install: info: reading /boot/grub2/i386-pc/boot.img.
grub2-install: info: reading /boot/grub2/i386-pc/core.img.
grub2-install: info: root is `(null)', dest is `(hd2)'.
grub2-install: info: Opening dest.
grub2-install: info: drive = -1.
grub2-install: error: disk `(hd2)' not found.
Move resolving of destination device name into main setup routine
so it is done consistently in both cases.