[BUG] error trying to configure a vm

debian8, trying to configure a vm:

2015-01-13 08:23:03+0100 [virtualbricks.gui.gui] Error while parsing qemu version
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/twisted/internet/_baseprocess.py", line 63, in maybeCallProcessEnded
    proto.processEnded(Failure(reason))
  File "/usr/lib/python2.7/dist-packages/twisted/internet/utils.py", line 95, in processEnded
    self.deferred.callback(self.s.getvalue())
  File "/usr/lib/python2.7/dist-packages/twisted/internet/defer.py", line 382, in callback
    self._startRunCallbacks(result)
  File "/usr/lib/python2.7/dist-packages/twisted/internet/defer.py", line 490, in _startRunCallbacks
    self._runCallbacks()
--- <exception caught here> ---
  File "/usr/lib/python2.7/dist-packages/twisted/internet/defer.py", line 577, in _runCallbacks
    current.result = callback(current.result, *args, **kw)
  File "/home/kapo/workspace/virtualbrick/virtualbricks/gui/gui.py", line 1070, in install_qemu_version
    container.pack_start(self._get_config_view(gui))
  File "/home/kapo/workspace/virtualbrick/virtualbricks/gui/gui.py", line 1154, in _get_config_view
    self.cbArgv0.set_cell_data_func(self.crf1, self.crf1.set_text)
exceptions.AttributeError: 'CellRendererFormattable' object has no attribute 'set_text'