Cannot create virtualenv when pip.conf contains user installs by default

[Samureus]

$ pip --version
pip 7.1.2 from /home/samo/.local/lib/python2.7/site-packages (python 2.7)

$ virtualenv --version
13.1.2

$ cat ~/.config/pip/pip.conf
[install]
user = yes

$ virtualenv test
New python executable in test/bin/python2.7
Also creating executable in test/bin/python
Installing setuptools, pip, wheel...
  Complete output from command /home/samo/.config/pip/test/bin/python2.7 -c "import sys, pip; sys...d\"] + sys.argv[1:]))" setuptools pip wheel:
  Can not perform a '--user' install. User site-packages are not visible in this virtualenv.
----------------------------------------
...Installing setuptools, pip, wheel...done.
Traceback (most recent call last):
  File "/home/samo/.pyenv/versions/2.7.10/bin/virtualenv", line 11, in <module>
    sys.exit(main())
  File "/home/samo/.pyenv/versions/2.7.10/lib/python2.7/site-packages/virtualenv.py", line 832, in main
    symlink=options.symlink)
  File "/home/samo/.pyenv/versions/2.7.10/lib/python2.7/site-packages/virtualenv.py", line 1004, in create_environment
    install_wheel(to_install, py_executable, search_dirs)
  File "/home/samo/.pyenv/versions/2.7.10/lib/python2.7/site-packages/virtualenv.py", line 969, in install_wheel
    'PIP_NO_INDEX': '1'
  File "/home/samo/.pyenv/versions/2.7.10/lib/python2.7/site-packages/virtualenv.py", line 910, in call_subprocess
    % (cmd_desc, proc.returncode))
OSError: Command /home/samo/.config/pip/test/bin/python2.7 -c "import sys, pip; sys...d\"] + sys.argv[1:]))" setuptools pip wheel failed with error code 1

[Samureus]

Documented here:
https://pip.readthedocs.org/en/latest/user_guide/#user-installs

Workaround:

$ export PIP_USER=FALSE
$ virtualenv test
New python executable in test/bin/python2.7
Also creating executable in test/bin/python
Installing setuptools, pip, wheel...done.
$ source test/bin/activate
(test)samo@Valinor:~$ pip list
pip (7.1.2)
setuptools (18.2)
wheel (0.24.0)

It also works with PIP_USER='0'. I guess the least obtrusive option to make it work is to append it after line 973:
https://github.com/pypa/virtualenv/blob/develop/virtualenv.py#L973

[Samureus]

Submitted pull request #803. (Travis did not complain, yay!)

#803

[Ivoz]

Cheers @Samureus merged in :)