Can't virt-install during the kickstart of the hypervisor

We install physical machines using cobbler/kickstart. On theses physical machines we need to be sure that one specific VM is installed and will be running on startup, so we tried to install the vm during a kickstart %post section without success so far. Our first try was dead simple: %post --log=/root/virt.log service libvirtd start virt-install ... --import %end But we had running in chroot ignoring request so we tried with --nochroot but still nothing. Any ideas? This is our client request, I'm not even sure this is really compliant with the cobbler way.