Traceback (most recent call last):
  File "/usr/share/software-center/piston_get_scagent_available_apps.py", line 134, in <module>
    scaclient = SoftwareCenterAgentAPI(cachedir=cachedir)
  File "/usr/lib/python2.7/dist-packages/piston_mini_client/__init__.py", line 218, in __init__
    self._httplib2_cache = httplib2.FileCache(cachedir, safe=safename)
  File "/usr/lib/python2.7/dist-packages/httplib2/__init__.py", line 684, in __init__
    os.makedirs(self.cache)
  File "/usr/lib/python2.7/os.py", line 157, in makedirs
    mkdir(name, mode)
OSError: [Errno 17] File exists: '/home/username/.cache/software-center/scaclient'