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

[Pascal Hambourg]

On 14/09/2025 at 09:28, Debian wrote:
> Am 13.09.25 um 15:49 schrieb Pascal Hambourg:
>>
>>> Copied from the initial report:
>>
>> Again, I do not see any line "linux /vmlinuz root=/dev/sda2" here.
> 
> What's about this two lines?
> 
>      linux /boot/vmlinuz-6.1.0-39-amd64 root=/dev/sdb2
>      initrd /boot/initrd.img-6.1.0-39-amd64

They do not match "linux /vmlinuz root=/dev/sda2" in any way: the kernel 
and initramfs pathnames and the root device are different.

>>>> Can you attach the full contents of /boot/grub/grub.cfg in Debian 12 
>>>> root filesytem ? 
>> This could be a bug in parsing menu entries from the foreign grub.cfg.
> 
> O.K.
> I have no idea where the informations are collected from.

Ideally, linux-boot-prober collects menu entry information (entry label, 
kernel path and parameters...) from grub.cfg when it is present.
I copied your Debian 12 grub.cfg to a test partition and 
linux-boot-prober and os-prober generate the expected kernel command line.

> I can only say that the update-grub scripts don't work for me, because 
> there are many boot partitions and I am cloning versions of an OS to 
> work with.

Maybe there are some leftovers from previous versions which cause this. 
I still cannot figure out how linux-boot-prober /dev/sdb2 could possibly 
generate the lines your reported in you previous post. While or after 
running it, could you check its debug logs in the system logs (in 
/var/log/syslog or with journalctl depending on which logging daemon you 
have) ?