I forgot to attach the file that should be installed in /usr/lib/os-probes/mounted/89grub
It returns "grub" as detected OS and it is parsed later in /etc/grub.d/30_os-prober
I forgot to attach the file that should be installed in /usr/lib/ os-probes/ mounted/ 89grub
It returns "grub" as detected OS and it is parsed later in /etc/grub. d/30_os- prober