Install grub-efi-amd64-dbg by entering the following commands in the terminal:
sudo apt update sudo apt install grub-efi-amd64-dbg
Description:
GRand Unified Bootloader, version 2 (EFI-AMD64 debug files)
This package contains debugging files for grub-efi-amd64-bin. You only need these if you are trying to debug GRUB using its GDB stub.
Homepage: http://www.gnu.org/software/grub/
Version: 2.02-2ubuntu8
Section: debug