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

[Dima Kogan <dkogan@debian.org>]

Package: installation-reports
Severity: grave

Hi. I just installed a bookworm candidate. This worked OK through
partitioning and reboot, but I cannot boot into the system.

This is an amd64 recent-ish laptop. The disk is a PCIe SSD, not SATA.

I'm installing from a USB drive. To make this work, I had to turn off
secure-boot and UEFI in the BIOS. I believe that the result of this is
the Debian partitioner defaulted to an MBR partition, not a GPT
partition.

The BIOS of this laptop only allows booting from the PCIe SSD in UEFI
mode (so I need to change the BIOS setting before even trying). But even
after that, the machine doesn't let me boot off that disk. Some
searching tells me this is because GPT partitions are required for UEFI
booting, but Debian made an MBR partition.

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.

Thanks.