[fuel-devops] Creation of hybrid (virtual+baremetal) environment fails: libvirtError: internal error: could not get interface XML description: unspecified error - errors in loading some config files

Creation of hybrid (virtual+baremetal) environment fails if I try to use other l2 network device as parent in my devops template:

2016-04-18 09:38:30,938 - ERROR __init__.py:66 -- get_admin_node_ip raised: libvirtError('internal error: could not get interface XML description: unspecified error - errors in loading some config files',)
Traceback: Traceback (most recent call last):
  File "/home/apanchenko/fuel-qa/fuelweb_test/__init__.py", line 59, in wrapped
    result = func(*args, **kwargs)
  File "/home/apanchenko/fuel-qa/fuelweb_test/models/environment.py", line 144, in get_admin_node_ip
    self.d_env.nodes(
  File "/home/apanchenko/fuel-qa/fuelweb_test/models/environment.py", line 219, in d_env
    self._virt_env.define()
  File "/home/apanchenko/fuel-devops-venv/local/lib/python2.7/site-packages/fuel_devops-3.0.0-py2.7.egg/devops/models/environment.py", line 141, in define
    group.define_networks()
  File "/home/apanchenko/fuel-devops-venv/local/lib/python2.7/site-packages/fuel_devops-3.0.0-py2.7.egg/devops/models/group.py", line 77, in define_networks
    l2_network_device.define()
  File "/home/apanchenko/fuel-devops-venv/local/lib/python2.7/site-packages/fuel_devops-3.0.0-py2.7.egg/devops/helpers/retry.py", line 27, in wrapper
    return func(*args, **kwargs)
  File "/home/apanchenko/fuel-devops-venv/local/lib/python2.7/site-packages/fuel_devops-3.0.0-py2.7.egg/devops/driver/libvirt/libvirt_driver.py", line 368, in define
    self.iface_define(name=bridge_name, vlanid=vlanid)
  File "/home/apanchenko/fuel-devops-venv/local/lib/python2.7/site-packages/fuel_devops-3.0.0-py2.7.egg/devops/helpers/retry.py", line 27, in wrapper
    return func(*args, **kwargs)
  File "/home/apanchenko/fuel-devops-venv/local/lib/python2.7/site-packages/fuel_devops-3.0.0-py2.7.egg/devops/driver/libvirt/libvirt_driver.py", line 508, in iface_define
    LibvirtXMLBuilder.build_iface_xml(name, ip, prefix, vlanid))
  File "/home/apanchenko/fuel-devops-venv/local/lib/python2.7/site-packages/libvirt.py", line 3472, in interfaceDefineXML
    if ret is None:raise libvirtError('virInterfaceDefineXML() failed', conn=self)
libvirtError: internal error: could not get interface XML description: unspecified error - errors in loading some config files

Steps to reproduce:

1. export DEVOPS_SETTINGS_TEMPLATE=baremetal_system_test.yaml (template is attached)
2. run system tests with devops 3.0 and ipmi driver (git sha: http://paste.openstack.org/show/494393/)

Expected result:

fuel devops environment is created, public networks uses eno2 phys NIC, admin network uses eno2 with 270 VLAN tag

Actual result:

fuel-devops fails to create networks