Comment 1 for bug 664709

For reference, here's what you get when you run the kernel upgrade in a terminal started from UCK:

> ...
> Setting up linux-image-2.6.35-22-generic (2.6.35-22.35) ...
> Running depmod.
> update-initramfs: Generating /boot/initrd.img-2.6.35-22-generic
> df: Warning: cannot read table of mounted file systems: No such file or directory
> cryptsetup: WARNING: could not determine root device from /etc/fstab
> Not updating initrd symbolic links since we are being updated/reinstalled
> (2.6.35-22.33 was configured last, according to dpkg)
> Not updating image symbolic links since we are being updated/reinstalled
> (2.6.35-22.33 was configured last, according to dpkg)
> Examining /etc/kernel/postinst.d.
> run-parts: executing /etc/kernel/postinst.d/initramfs-tools 2.6.35-22-generic /boot/vmlinuz-2.6.35-22-generic
> run-parts: executing /etc/kernel/postinst.d/nvidia-common 2.6.35-22-generic /boot/vmlinuz-2.6.35-22-generic
> run-parts: executing /etc/kernel/postinst.d/pm-utils 2.6.35-22-generic /boot/vmlinuz-2.6.35-22-generic
> run-parts: executing /etc/kernel/postinst.d/update-notifier 2.6.35-22-generic /boot/vmlinuz-2.6.35-22-generic
> run-parts: executing /etc/kernel/postinst.d/zz-update-grub 2.6.35-22-generic /boot/vmlinuz-2.6.35-22-generic
> /usr/sbin/grub-probe: error: cannot find a device for / (is /dev mounted?).
> run-parts: /etc/kernel/postinst.d/zz-update-grub exited with return code 1
> Failed to process /etc/kernel/postinst.d at /var/lib/dpkg/info/linux-image-2.6.35-22-generic.postinst line 1010.
> dpkg: error processing linux-image-2.6.35-22-generic (--configure):
> subprocess installed post-installation script returned error exit status 2
> Errors were encountered while processing:
> linux-image-2.6.35-22-generic
> E: Sub-process /usr/bin/dpkg returned an error code (1)

So essentially what's happening is that the update-grub command is aborting because it cannot determine the root file system.

As a workaround you can (temporarily) move the /etc/kernel/postinst.d/zz-update-grub procedure someplace else while updating the kernel from a terminal started from UCK (don't forget to restore it afterwards!) - this will make the kernel upgrade succeed (and on the live system grub is not used anyway - so configuring it doesn't really make sense in UCK).

I've no idea yet how to fix the issue permanently, though...