Ошибка зернышка при установке: virtualenv, django и обновляющий зернышко

Я пытаюсь запустить проект Django, не знайте то, что я делаю, чтобы быть честным. Я запустил после учебного руководства. Установленный python 3.6 (хотя это показывает 2.7, вероятно, шел с человечностью). И затем установленное зернышко и попробованный для установки virtualenv и Django. Получил эту ошибку:

$ sudo pip install virtualenv
The directory '/home/dutek/.cache/pip/http' or its parent directory is not owned by the current user and the cache has been disabled. Please check the permissions and owner of that directory. If executing pip with sudo, you may want sudo's -H flag.
The directory '/home/dutek/.cache/pip' or its parent directory is not owned by the current user and caching wheels has been disabled. check the permissions and owner of that directory. If executing pip with sudo, you may want sudo's -H flag.
Collecting virtualenv
Exception:
Traceback (most recent call last):
File "/usr/lib/python2.7/dist-packages/pip/basecommand.py", line 215, in main
status = self.run(options, args)
File "/usr/lib/python2.7/dist-packages/pip/commands/install.py", line 317, in run
requirement_set.prepare_files(finder)
File "/usr/lib/python2.7/dist-packages/pip/req/req_set.py", line 370, in prepare_files
ignore_dependencies=self.ignore_dependencies))
File "/usr/lib/python2.7/dist-packages/pip/req/req_set.py", line 522, in _prepare_file
finder, self.upgrade, require_hashes)
File "/usr/lib/python2.7/dist-packages/pip/req/req_install.py", line 268, in populate_link
self.link = finder.find_requirement(self, upgrade)
File "/usr/lib/python2.7/dist-packages/pip/index.py", line 442, in find_requirement
all_candidates = self.find_all_candidates(req.name)
File "/usr/lib/python2.7/dist-packages/pip/index.py", line 400, in find_all_candidates
for page in self._get_pages(url_locations, project_name):
File "/usr/lib/python2.7/dist-packages/pip/index.py", line 545, in _get_pages
page = self._get_page(location)
File "/usr/lib/python2.7/dist-packages/pip/index.py", line 648, in _get_page
return HTMLPage.get_page(link, session=self.session)
File "/usr/lib/python2.7/dist-packages/pip/index.py", line 757, in get_page
"Cache-Control": "max-age=600",
File "/usr/share/python-wheels/requests-2.10.0-py2.py3-none-any.whl/requests/sessions.py", line 487, in get
return self.request('GET', url, **kwargs)
File "/usr/lib/python2.7/dist-packages/pip/download.py", line 378, in request
return super(PipSession, self).request(method, url, *args, **kwargs)
File "/usr/share/python-wheels/requests-2.10.0-py2.py3-none-any.whl/requests/sessions.py", line 475, in request
resp = self.send(prep, **send_kwargs)
File "/usr/share/python-wheels/requests-2.10.0-py2.py3-none-any.whl/requests/sessions.py", line 585, in send
r = adapter.send(request, **kwargs)
File "/usr/share/python-wheels/CacheControl-0.11.5-py2.py3-none-any.whl/cachecontrol/adapter.py", line 46, in send
resp = super(CacheControlAdapter, self).send(request, **kw)
File "/usr/share/python-wheels/requests-2.10.0-py2.py3-none-any.whl/requests/adapters.py", line 403, in send
timeout=timeout
File "/usr/share/python-wheels/urllib3-1.15.1-py2.py3-none-any.whl/urllib3/connectionpool.py", line 623, in urlopen
_stacktrace=sys.exc_info()[2])
File "/usr/share/python-wheels/urllib3-1.15.1-py2.py3-none-any.whl/urllib3/util/retry.py", line 236, in increment
total -= 1
TypeError: unsupported operand type(s) for -=: 'Retry' and 'int'
You are using pip version 8.1.2, however version 9.0.1 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.

Я действительно попытался "победить установку - зернышко обновления", но получил тот же тип ошибки.