===== Parallel build; waiting for Lubuntu mirror to sync =====
Mon Jan  8 04:52:09 UTC 2018
===== Building britney =====
Mon Jan  8 04:52:09 UTC 2018
make: Entering directory '/srv/cdimage.ubuntu.com/britney/update_out'
make: Nothing to be done for 'all'.
make: Leaving directory '/srv/cdimage.ubuntu.com/britney/update_out'
===== Extracting debootstrap scripts =====
Mon Jan  8 04:52:09 UTC 2018
===== Germinating =====
Mon Jan  8 04:52:10 UTC 2018
Germinating for artful/amd64 ...
Traceback (most recent call last):
  File "/srv/cdimage.ubuntu.com/bin/../lib/cdimage/build.py", line 758, in build_image_set_locked
    germination.run()
  File "/srv/cdimage.ubuntu.com/bin/../lib/cdimage/germinate.py", line 246, in run
    self.germinate_project(self.config.project)
  File "/srv/cdimage.ubuntu.com/bin/../lib/cdimage/germinate.py", line 239, in germinate_project
    self.germinate_arch(project, arch)
  File "/srv/cdimage.ubuntu.com/bin/../lib/cdimage/germinate.py", line 210, in germinate_arch
    env=dict(os.environ, GIT_TERMINAL_PROMPT=0))
  File "/srv/cdimage.ubuntu.com/bin/../lib/cdimage/proxy.py", line 60, in proxy_check_call
    subprocess.check_call(*args, **kwargs)
  File "/usr/lib/python2.7/subprocess.py", line 536, in check_call
    retcode = call(*popenargs, **kwargs)
  File "/usr/lib/python2.7/subprocess.py", line 523, in call
    return Popen(*popenargs, **kwargs).wait()
  File "/usr/lib/python2.7/subprocess.py", line 711, in __init__
    errread, errwrite)
  File "/usr/lib/python2.7/subprocess.py", line 1343, in _execute_child
    raise child_exception
TypeError: execve() arg 3 contains a non-string value