[Libvir] First virConnectOpen() failed

Hi all, I've compiled libvirt from the head, running tests failed with: first virConnectOpen() failed I've traced it to a failure of xs_daemon_open_readonly() that returns 0. What would be a problem, please? xend is running, I see dom0 and can create domUs etc... I use Debian unstable Xen packages. Thanks in advance, Glenn P.S. I'm not a Xen expert, kind of intermediate/advanced user.