<p>virtualenv falla: la rueda pip de setuptools falló con el código de error 2</p>

Estoy ejecutando Ubuntu-12.04:

pip --versión
pip 8.0.2 de /usr/local/lib/python2.7/dist-packages (python 2.7)

virtualenv --versión
14.0.6

virtualenv no puede crear el entorno. No sé por qué cree que se supone que debe usar pip 7.0.1, cuando está instalado pip 8.0.2.
Intenté reinstalar pip (es decir, eliminar el paquete apt, instalar a través de ez_setup), virtualenv, nada funcionó.
En otras máquinas, 14.0.6 funcionó bien, es solo esta la que me está haciendo pasar un mal rato.
¡Cualquier ayuda sería apreciada!

Adjunto el registro y sigo el entorno pip:

Iniciar sesión

virtualenv --system-site-packages /tmp/venv
New python executable in /tmp/venv/bin/python
Installing setuptools, pip, wheel...
  Complete output from command /tmp/venv/bin/python -c "import sys, pip; sys...d\"] + sys.argv[1:]))" setuptools pip wheel:
  You are using pip version 7.0.1, however version 8.0.2 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.
Collecting setuptools
/usr/local/lib/python2.7/dist-packages/virtualenv_support/pip-7.0.1-py2.py3-none-any.whl/pip/_vendor/requests/packages/urllib3/util/ssl_.py:90: InsecurePlatformWarning: A true SSLContext object is not available. This prevents urllib3 from configuring SSL appropriately and may cause certain SSL connections to fail. For more information, see https://urllib3.readthedocs.org/en/latest/security.html#insecureplatformwarning.
Exception:
Traceback (most recent call last):
  File "/usr/local/lib/python2.7/dist-packages/virtualenv_support/pip-7.0.1-py2.py3-none-any.whl/pip/basecommand.py", line 223, in main
    status = self.run(options, args)
  File "/usr/local/lib/python2.7/dist-packages/virtualenv_support/pip-7.0.1-py2.py3-none-any.whl/pip/commands/install.py", line 291, in run
    wb.build(autobuilding=True)
  File "/usr/local/lib/python2.7/dist-packages/virtualenv_support/pip-7.0.1-py2.py3-none-any.whl/pip/wheel.py", line 704, in build
    self.requirement_set.prepare_files(self.finder)
  File "/usr/local/lib/python2.7/dist-packages/virtualenv_support/pip-7.0.1-py2.py3-none-any.whl/pip/req/req_set.py", line 317, in prepare_files
    functools.partial(self._prepare_file, finder))
  File "/usr/local/lib/python2.7/dist-packages/virtualenv_support/pip-7.0.1-py2.py3-none-any.whl/pip/req/req_set.py", line 304, in _walk_req_to_install
    more_reqs = handler(req_to_install)
  File "/usr/local/lib/python2.7/dist-packages/virtualenv_support/pip-7.0.1-py2.py3-none-any.whl/pip/req/req_set.py", line 439, in _prepare_file
    req_to_install.populate_link(finder, self.upgrade)
  File "/usr/local/lib/python2.7/dist-packages/virtualenv_support/pip-7.0.1-py2.py3-none-any.whl/pip/req/req_install.py", line 244, in populate_link
    self.link = finder.find_requirement(self, upgrade)
  File "/usr/local/lib/python2.7/dist-packages/virtualenv_support/pip-7.0.1-py2.py3-none-any.whl/pip/index.py", line 486, in find_requirement
    all_versions = self._find_all_versions(req.name)
  File "/usr/local/lib/python2.7/dist-packages/virtualenv_support/pip-7.0.1-py2.py3-none-any.whl/pip/index.py", line 435, in _find_all_versions
    formats = fmt_ctl_formats(self.format_control, canonical_name)
  File "/usr/local/lib/python2.7/dist-packages/virtualenv_support/pip-7.0.1-py2.py3-none-any.whl/pip/index.py", line 1260, in fmt_ctl_formats
    if canonical_name in fmt_ctl.only_binary:
AttributeError: 'str' object has no attribute 'only_binary'

----------------------------------------

...Installing setuptools, pip, wheel...done.
Traceback (most recent call last):
  File "/usr/local/bin/virtualenv", line 11, in <module>
    sys.exit(main())
  File "/usr/local/lib/python2.7/dist-packages/virtualenv.py", line 705, in main
    symlink=options.symlink)
  File "/usr/local/lib/python2.7/dist-packages/virtualenv.py", line 924, in create_environment
    download=download,
  File "/usr/local/lib/python2.7/dist-packages/virtualenv.py", line 877, in install_wheel
    call_subprocess(cmd, show_stdout=False, extra_env=env)
  File "/usr/local/lib/python2.7/dist-packages/virtualenv.py", line 783, in call_subprocess
    % (cmd_desc, proc.returncode))
OSError: Command /tmp/venv/bin/python -c "import sys, pip; sys...d\"] + sys.argv[1:]))" setuptools pip wheel failed with error code 2

lista de pepitas

APScheduler (2.1.2)
apt-xapian-index (0.44)
boto (2.2.2)
chardet (2.0.1)
Cheetah (2.4.4)
cloud-init (0.6.3)
command-not-found (0.2.44)
configobj (4.7.2)
demjson (1.6)
distribute (0.6.24dev-r0)
euca2ools (2.0.0)
futures (2.2.0)
GnuPGInterface (0.3.2)
google-api-python-client (1.3.1)
httplib2 (0.9)
iotop (0.4.4)
keyring (0.9.2)
Landscape-Client (14.12)
language-selector (0.1)
launchpadlib (1.9.12)
lazr.restfulclient (0.12.0)
lazr.uri (1.0.3)
lxml (3.2.3)
M2Crypto (0.21.1)
Markdown (2.6.5)
oauth (1.0.1)
oauth2client (1.4.6)
PAM (0.4.2)
paramiko (1.7.7.1)
pika (0.9.14)
pip (8.0.2)
pyasn1 (0.1.7)
pyasn1-modules (0.0.5)
pycrypto (2.6.1)
pycurl (7.19.5)
pyes (0.99.6)
pymongo (2.8)
pyOpenSSL (0.12)
pyserial (2.5)
python-apt (0.8.3ubuntu7.3)
python-debian (0.1.21ubuntu1)
PyYAML (3.10)
pyzabbix (0.7.2)
requests (2.5.1)
rsa (3.1.4)
setuptools (18.7)
simplejson (3.6.5)
six (1.9.0)
tabulate (0.7.5)
thrift (0.9.0)
tinys3 (0.1.11)
tldextract (1.2.2)
Twisted-Core (11.1.0)
Twisted-Web (11.1.0)
ufw (0.31.1.post1)
unattended-upgrades (0.1)
unicodecsv (0.9.4)
uritemplate (0.6)
urllib3 (1.10)
virtualenv (13.1.0)
wadllib (1.3.0)
wheel (0.29.0)
XlsxWriter (0.7.2)
zbxsend (0.1.6)
zope.interface (3.6.1)