update-grub in chroot doesn't pick up all linux installs

[bcbc]

This is not likely an issue for Wubi users, but if you have other linux installs on the target drive, they are not picked up by os-prober within the chroot. It's not a big issue since both the migrated install and the Windows install are picked up and running "sudo update-grub" after booting will correct.

[bcbc]

When you migrate a non-wubi install to a new partition on the same drive, the 'update-grub' in the chroot for the migrated install doesn't pick up the source install. i.e. if there are no other OSes on the computer other than the source and migrated install, and you install the bootloader pointing to the migrated install, grub will suppress display of the grub menu and boot directly to the migrated install. Only running 'update-grub' after booting will detect the source install and set the grub menu to display.