Bug#1093820: grub-efi: boot ends in grub command prompt after fresh debian install

[Pascal Hambourg]

On 23/01/2025 at 00:07, M. Dietrich wrote:
> 
> after installing a debian
> from recently downloaded iso the system boots fine into grub but gets
> stuck in the grub command prompt.

This is Ubuntu's leftover GRUB booting and failing to find its deleted 
boot/root partition, not Debian's GRUB. You could have checked 
cmdpath/fw_path with "set" at GRUB prompt.

> i installed debian in the same partition where previously ubuntu was
> installed but did not know about additional files for efi in partition
> 1.
> 
> after some investigations i found that there was a leftover from the
> ubuntu installation in directory /boot/efi/EFI/ubuntu

And not in /boot/efi/EFI/BOOT ?

> efibootmgr showed values that seemed to be fine (while there was an
> ubuntu entry) and BootOrder pointed to the debian Boot entry.

What does this mean exactly ?

> after removing that ubuntu directory grub works fine.
> 
> i dont know if it was just my mistake not to delete that dir when wiping
> ubuntu from the system  or the debian installer should notice that or

Notice what ?

> grub should not screw up when its not configured to take that dir into
> account.

GRUB did not screw up. The UEFI firmware just booted the wrong GRUB 
until you deleted it.