[libvirt] libvirtlight problem with Xen

I'm trying to use virt-manager with Xen. My Dom0 is Debian 8. When I create a DomU (Ubuntu Trusty) as a PV guest, the boot fails with an error saying that libvirtlight failed to connect. The opinion from the virt-manager list group is that the problem is libvirt, not virt-manager. I've googled around, and have seen old posts about this, but these seem to claim that the problem has resolved. Solution? Thanks Eric