Aaaaah, my router doesn't have udev! In osdep/linux/hostdisk.c:sysfs_partition_path(), calling udevadm through grub_util_exec_pipe() will fail and fall through to *unpatched* exit(). Sounds plausible?
If my guess is right, perhaps sid is affected too. Sorry I don't have any testbed, if anyone could confirm please adjust bugtitle and severity accordingly. I'm not sure about appropriate value. ... I thought a debian installation without udev is still not illegal nor broken ... Thanks,
