Errno 13 运行 virtualenv 时权限被拒绝

当尝试在 Mac OS X 上使用brew安装的 Python 2.7 创建 virtualenv 时，出现以下错误：

Could not install packages due to an EnvironmentError: 
  [Errno 13] Permission denied: '/lib'

完整输出：

▶ virtualenv ./virtualenv               
New python executable in /Users/alexharvey/git/home/sam-test/virtualenv/bin/python2.7
Also creating executable in /Users/alexharvey/git/home/sam-test/virtualenv/bin/python
Installing setuptools, pip, wheel...                    

  Complete output from command /Users/alexharvey/gi...ualenv/bin/python2.7 - setuptools pip wheel:
  Looking in links: /usr/local/lib/python2.7/site-packages, /usr/local/lib/python2.7/site-packages/virtualenv_support, /usr/local/lib/python2.7/site-packages/virtualen
v_support                                                                                                                                                             
Collecting setuptools                                                       
  Using cached https://files.pythonhosted.org/packages/37/06/754589caf971b0d2d48f151c2586f62902d93dc908e2fd9b9b9f6aa3c9dd/setuptools-40.6.3-py2.py3-none-any.whl      
Collecting pip                                                          
Collecting wheel                                                                                                                                                      
  Using cached https://files.pythonhosted.org/packages/ff/47/1dfa4795e24fd6f93d5d58602dd716c3f101cfd5a77cd9acbe519b44a0a9/wheel-0.32.3-py2.py3-none-any.whl           
Installing collected packages: setuptools, pip, wheel                                                                                                                 
Could not install packages due to an EnvironmentError: [Errno 13] Permission denied: '/lib'
Consider using the `--user` option or check the permissions.                                                                                                          

----------------------------------------
...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/site-packages/virtualenv.py", line 762, in main                                                                                      
    symlink=options.symlink,
  File "/usr/local/lib/python2.7/site-packages/virtualenv.py", line 1015, in create_environment
    install_wheel(to_install, py_executable, search_dirs, download=download)
  File "/usr/local/lib/python2.7/site-packages/virtualenv.py", line 968, in install_wheel
    call_subprocess(cmd, show_stdout=False, extra_env=env, stdin=SCRIPT)                                                                                              
  File "/usr/local/lib/python2.7/site-packages/virtualenv.py", line 854, in call_subprocess
    raise OSError("Command {} failed with error code {}".format(cmd_desc, proc.returncode))
OSError: Command /Users/alexharvey/gi...ualenv/bin/python2.7 - setuptools pip wheel failed with error code 1

我发现类似的问题以前经常被问到（例如here https://stackoverflow.com/questions/24504231/whats-causing-this-error-when-i-try-and-install-virtualenv-ioerror-errno-13）但赞成的答案似乎建议使用sudo，这显然是错误的。

请注意，我已遵循此页面上的建议：在 Mac OS X 上有效使用 python http://blog.manbolo.com/2014/09/27/use-python-effectively-on-os-x.

我该如何解决这个问题（不使用 sudo）？

正如评论中所建议的，自定义 Distutils 配置文件存在问题。该文件显然可以位于三个位置之一（ref https://docs.python.org/2.5/inst/config-syntax.html):

• system: <prefix>/lib/pythonver/distutils/distutils.cfg
• personal: $HOME/.pydistutils.cfg
• local: setup.cfg

同时我创建了一个setup.cfg根据这个SO答案here https://stackoverflow.com/a/44728772/3787051内容：

[install]
prefix=

我不再记得为什么我查阅了这个答案，或者为什么我把那个文件放在那里，但是在我删除它之后，virtualenv 再次工作正常，并且我没有再遇到任何问题。