pip install broken

[arnaud gaboury <arnaud.gaboury@xxxxxxxxx>]

python-pip 6.0.6-1

Please find below error messages when runiing some pip commands. pip
have been working like a charm until now. A bug or some
misconfigurations ??

---------------------------------
$ pip install websocket-client

Exception:
Traceback (most recent call last):
  File "/usr/lib/python3.4/site-packages/pip/basecommand.py", line 232, in main
    status = self.run(options, args)
  File "/usr/lib/python3.4/site-packages/pip/commands/install.py",
line 339, in run
    requirement_set.prepare_files(finder)
  File "/usr/lib/python3.4/site-packages/pip/req/req_set.py", line
229, in prepare_files
    req_to_install.check_if_exists()
  File "/usr/lib/python3.4/site-packages/pip/req/req_install.py", line
928, in check_if_exists
    self.satisfied_by = pkg_resources.get_distribution(self.req)
  File "/usr/lib/python3.4/site-packages/pip/_vendor/pkg_resources/__init__.py",
line 461, in get_distribution
    dist = get_provider(dist)
  File "/usr/lib/python3.4/site-packages/pip/_vendor/pkg_resources/__init__.py",
line 341, in get_provider
    return working_set.find(moduleOrReq) or require(str(moduleOrReq))[0]
  File "/usr/lib/python3.4/site-packages/pip/_vendor/pkg_resources/__init__.py",
line 870, in require
    needed = self.resolve(parse_requirements(requirements))
  File "/usr/lib/python3.4/site-packages/pip/_vendor/pkg_resources/__init__.py",
line 740, in resolve
    env = Environment(self.entries)
  File "/usr/lib/python3.4/site-packages/pip/_vendor/pkg_resources/__init__.py",
line 927, in __init__
    self.scan(search_path)
  File "/usr/lib/python3.4/site-packages/pip/_vendor/pkg_resources/__init__.py",
line 957, in scan
    self.add(dist)
  File "/usr/lib/python3.4/site-packages/pip/_vendor/pkg_resources/__init__.py",
line 977, in add
    dists.sort(key=operator.attrgetter('hashcmp'), reverse=True)
TypeError: unorderable types: NoneType() < str()
-----------------------------------------------------
gabx@hortensia ➤➤ ~ % pip install --verbose
There was an error checking the latest version of pip
Traceback (most recent call last):
  File "/usr/lib/python3.4/site-packages/pip/utils/outdated.py", line
129, in pip_version_check
    state.save(pypi_version, current_time)
  File "/usr/lib/python3.4/site-packages/pip/utils/outdated.py", line
76, in save
    with open(self.statefile_path) as statefile:
FileNotFoundError: [Errno 2] No such file or directory:
'/home/gabx/.cache/pip/selfcheck.json'
-------------------------------------------------------

Thank you for help