I tried to install gentoo via LiveCD but it fails. At boot prompt, I specified: gentoo dolvm2 .
From boot messages I saw that my volume group vg00 was activated. But later on specifying the partition layout, I could not continue as my volume group was not shown. The only free space I have is on a logical volume in this volume group. That will require / on lvm too ;-) .
That's not a bug. The installer just flat out doesn't support LVM, software raid, etc. yet. It probably won't for quite a while.