Mountain Lion Server guest on Mountain Lion host

[Jeff Porten]

I'm running into brick walls trying to set up a VM for OSXS 10.8.1, running under OS X client 10.8.1, VBox 4.1.20.

Had no trouble setting up VMs for Ubuntu 12 or Windows 8, but I can't figure out how to mount a new Mac VM with a working boot system. Have tried mounting the InstallESD.dmg from inside the Mountain Lion installer; copying the installer to a USB drive and mounting it there; converting the DMG image to CDR and ISO. All with no dice: booting the Mac VM gives me errors ranging from "no bootable drive" to "unable to read the drive."

Read a bunch of documentation and have fiddled with 777 permissions and VBoxManage, to no avail. I'm probably missing something obvious. Anyone care to tell me what that is?