Bug#1033678: installation-reports: Unbootable install: MBR partition unusable with UEFI

[Dima Kogan <dkogan@debian.org>]

Pascal Hambourg <pascal@plouf.fr.eu.org> writes:

> On 30/03/2023 at 01:21, Dima Kogan wrote:
>> I had to turn off
>> secure-boot and UEFI in the BIOS.
>
> Why ? What happens if UEFI boot is enabled ?

If UEFI was enabled, the USB device isn't seen by the machine in its
list of valid boot devices


> How did you prepare the USB drive ? What installation image did you
> use (full file name and URL please) ?

>From yesterday's email:

  I downloaded this:

    debian-bookworm-DI-alpha2-amd64-netinst.iso

  from here:

    https://cdimage.debian.org/cdimage/bookworm_di_alpha2/amd64/iso-cd/

  and I wrote that .iso to /dev/sde

I did "cp debian-bookworm-DI-alpha2-amd64-netinst.iso /dev/sde"


>> I'm not 100% sure of the exact cause. But I suspect strongly is that
>> booting the install media without UEFI broke installing to an UEFI-only
>> disk.
>
> If the installer was booted in BIOS/legacy mode, it installed GRUB for
> legacy boot.

Was this a choice the installer made, or was it the only option? I don't
actually have a workaround yet. And if the installer had a check box to
ask for a GPT even though the install media was booted without UEFI,
then I could at least get this working after some fiddling.