Ubuntu would not boot after update to Oneiric

[Nils Durner]

The update process to Oneiric reported that it was unable to update grub.
Now, the boot screen is just black with a blinking cursor, no traces of grub or the kernel.

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# parted
GNU Parted 2.3
Using /dev/sda
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) print
Model: ATA WDC WD2001FASS-0 (scsi)
Disk /dev/sda: 2000GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt

Number Start End Size File system Name Flags
 1 1049kB 4000MB 3999MB linux-swap(v1)
 2 4000MB 2000GB 1996GB xfs
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Reinstalling grub in chroot fails:
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root@ubuntu:/# grub-install /dev/sda
/usr/sbin/grub-setup: warn: This GPT partition label has no BIOS Boot Partition; embedding won't be possible!.
/usr/sbin/grub-setup: warn: Embedding is not possible. GRUB can only be installed in this setup by using blocklists. However, blocklists are UNRELIABLE and their use is discouraged..
/usr/sbin/grub-setup: error: will not proceed with blocklists.
root@ubuntu:/# grub-install /dev/sda2
/usr/sbin/grub-setup: error: /dev/sda appears to contain a xfs filesystem which isn't known to reserve space for DOS-style boot. Installing GRUB there could result in FILESYSTEM DESTRUCTION if valuable data is overwritten by grub-setup (--skip-fs-probe disables this check, use at your own risk).
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Creating a new boot partition with ext2 yields the same grub message about blocklists

[Nils Durner (ndurner)]

Is GPT+XFS+grub not supported anymore?