Bug#1114894: OS-Prober generates not running entries for Debian 12

[Pascal Hambourg]

On 13/09/2025 at 12:51, Debian wrote:
> Am 13.09.25 um 10:55 schrieb Pascal Hambourg:
>> I do not see any such entry in grub.cfg in your initial report.
> 
> Copied from the initial report:

Again, I do not see any line "linux /vmlinuz root=/dev/sda2" here.

>> Can you attach the full contents of /boot/grub/grub.cfg in Debian 12 
>> root filesytem ? 
> 
> This is a bug for Debian 13 and not for Debian 12.

This could be a bug in parsing menu entries from the foreign grub.cfg.

>>> The error occurs after the upgrade when grub has been installed in 
>>> Debian 13.
>>
>> Which upgrade ?
> 
> It seems to be confusing for you. :-)
(...)
> Debian 12 is installed in /dev/sdb2 and has been copied to /dev/sdb5.

How was I supposed to know about that ?

> It was not easy to boot the copy in /dev/sdb5

If you used os-prober to generate menu entries for the copy, the 
grub.cfg copy originally contained the wrong UUID in the kernel command 
line and os-prober imported them, so the generated menu entries actually 
mounted the original root partition.