Strange building of partition image

Hello, I am attempting to build Haiku under Gentoo GNU/Linux, direct to partition. That is, /dev/hda14 has permissions set to allow me to write to it, and UserBuildConfig is as below. However, when GRUB comes to boot from the partition it says that it can't load the image. The command jam @disk mount is able to view the partition, but it shows one top-level directory myfs, under which are apps, common, develop, home, optional, system and var. Surely those sub-directories should actually be in the root, and there should not be the directory myfs ?

Grub entry:

title Haiku
rootnoverify (hd0,13)
chainloader +1

UserBuildConfig:

HAIKU_IMAGE_HOST_NAME = pimple ;

AddUserToHaikuImage mounty : 573 : 100 : /boot/home/mounty : /bin/bash : "Michael Mounteney" ;

AddOptionalHaikuImagePackages Beam ;
AddOptionalHaikuImagePackages BeHappy ;
AddOptionalHaikuImagePackages BePDF ;
AddOptionalHaikuImagePackages Firefox ;
AddOptionalHaikuImagePackages NetSurf ;
AddOptionalHaikuImagePackages OpenSSL ;
AddOptionalHaikuImagePackages OpenSSH ;
AddOptionalHaikuImagePackages Pe ;
AddOptionalHaikuImagePackages Vision ;
AddOptionalHaikuImagePackages Welcome ;
AddOptionalHaikuImagePackages WonderBrush ;

# Add symlink/file (timezone and keymap settings) to the image.
AddSymlinkToHaikuImage home config settings
: /boot/system/etc/timezones/Australia/Adelaide : timezone ;

# AddFilesToHaikuImage home config settings : "US-International" : Key_map ;

DefineBuildProfile disk : disk : "/dev/hda14" ;

HAIKU_IMAGE_NAME = hda14 ;
HAIKU_IMAGE_DIR = /dev ;

switch $(HAIKU_BUILD_PROFILE) {
case "disk" : {
AddOptionalHaikuImagePackages Beam BeBook BeHappy BePDF Bluetooth CVS
Development Firefox LibLayout Links NetSurf OpenSound OpenSSH
OpenSSL P7zip Pe Perl Subversion UserlandFS Vision VLC Welcome
WonderBrush Yasm ;
}

case "vmware" : {
HAIKU_IMAGE_SIZE = 900 ;
}
}

HAIKU_BUILD_FEATURE_SSL = 1 ;