Comment 3 for bug 732149

Hi! I've just updated Natty after about a week, and my postinstall scripts fail with
Generating grub.cfg ...
/usr/sbin/grub-probe: error: unknown filesystem.

Now I've purged everything grub, and reinstalled grub-common (1.99~rc1-4ubuntu1), but still
$ sudo grub-probe /
grub-probe: error: unknown filesystem.

I can't install grub-pc, because it aborts with
Creating config file /etc/default/grub with new version
/usr/sbin/grub-probe: error: unknown filesystem.
Auto-detection of a filesystem of /dev/sda3 failed.
Please report this together with the output of "/usr/sbin/grub-probe --device-map="/boot/grub/device.map" --target=fs -v /boot/grub" to <email address hidden>

Note that I don't even have /boot/grub/device.map. And I have btrfs root, which contains /boot. Is this a regression in the package? And what should I do before reboot? :-)