Traceback (most recent call last):
  File "/lu/buildbot/yocto-autobuilder/lib/python2.7/site-packages/Twisted-12.2.0-py2.7-linux-x86_64.egg/twisted/internet/defer.py", line 368, in callback
    self._startRunCallbacks(result)
  File "/lu/buildbot/yocto-autobuilder/lib/python2.7/site-packages/Twisted-12.2.0-py2.7-linux-x86_64.egg/twisted/internet/defer.py", line 464, in _startRunCallbacks
    self._runCallbacks()
  File "/lu/buildbot/yocto-autobuilder/lib/python2.7/site-packages/Twisted-12.2.0-py2.7-linux-x86_64.egg/twisted/internet/defer.py", line 551, in _runCallbacks
    current.result = callback(current.result, *args, **kw)
  File "/lu/buildbot/yocto-autobuilder/lib/python2.7/site-packages/Twisted-12.2.0-py2.7-linux-x86_64.egg/twisted/internet/defer.py", line 1101, in gotResult
    _inlineCallbacks(r, g, deferred)
--- <exception caught here> ---
  File "/lu/buildbot/yocto-autobuilder/lib/python2.7/site-packages/Twisted-12.2.0-py2.7-linux-x86_64.egg/twisted/internet/defer.py", line 1045, in _inlineCallbacks
    result = g.send(result)
  File "/lu/buildbot/yocto-autobuilder/lib/python2.7/site-packages/buildbot-0.8.8-py2.7.egg/buildbot/steps/source/yoctogit.py", line 196, in full
    self.mirrorexists = yield self._mirrorExists()
  File "/lu/buildbot/yocto-autobuilder/lib/python2.7/site-packages/buildbot-0.8.8-py2.7.egg/buildbot/steps/source/yoctogit.py", line 565, in _mirrorExists
    mirror = self.mirrordir + "/" + self.repourl.replace("git://", "") + "/"
exceptions.TypeError: unsupported operand type(s) for +: 'NoneType' and 'str'