Traceback (most recent call last):
  File "/usr/share/software-center/piston_generic_helper.py", line 203, in <module>
    api = klass(cachedir=cachedir)
  File "/usr/lib/python2.7/dist-packages/piston_mini_client/__init__.py", line 240, in __init__
    self._httplib2_cache = httplib2.FileCache(cachedir, safe=safename)
  File "/usr/lib/python2.7/dist-packages/httplib2/__init__.py", line 686, 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/piston-helper'