Problem with zfsloader on 9.2-BETA2

[J David]

In order to test ZFS on the upcoming 9.2 release, we upgraded a
non-production 8.4 root-on-ZFS fileserver to 9.2-BETA2.

The result was a non-bootable system.  The first problem was
gptzfsboot, but that was our fault… it never got upgraded when we
switched to feature flags.  So some time with the 8.4 live CD (the 9.x
CD's do not boot on this system -- kern/162160 ) solved that.

But the system still wouldn't boot, moving on to:

ZFS: can't find pool by guid
ZFS: can't find pool by guid

We got around this by interrupting the stage1 loader and invoking
data/root:/boot/zfsloader.old instead.  Then we moved the 9.2
zfsloader out of the way and restored the 8.4 loader.

So this system only boots with the 9.2 gptzfsboot and the 8.4 zfsloader.

To the best of my knowledge, there is nothing broken or out of date
with this zpool:

$ zpool status
  pool: data
 state: ONLINE
  scan: resilvered 451G in 70h36m with 0 errors on Fri Feb 17 00:26:19 2012
config:

	NAME          STATE     READ WRITE CKSUM
	data          ONLINE       0     0     0
	  raidz2-0    ONLINE       0     0     0
	    da2p1     ONLINE       0     0     0
	    da3p1     ONLINE       0     0     0
	    da4p1     ONLINE       0     0     0
	    da5p1     ONLINE       0     0     0
	    da6p1     ONLINE       0     0     0
	    da7p1     ONLINE       0     0     0
	logs
	  gpt/slog0   ONLINE       0     0     0
	cache
	  gpt/cache1  ONLINE       0     0     0

errors: No known data errors
$ zpool upgrade
This system supports ZFS pool feature flags.

All pools are formatted using feature flags.

Every feature flags pool has all supported features enabled.


Does anyone know why the 9.2 zfsloader won't load it?

Thanks!