创建一个新的virtualenv将授予

Question

我在运行virtualenv newvenv时得到以下输出。你知道吗

Traceback (most recent call last):
  File "/usr/local/bin/virtualenv", line 5, in <module>
    from pkg_resources import load_entry_point
  File "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 2727, in <module>
    add_activation_listener(lambda dist: dist.activate())
  File "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 700, in subscribe
    callback(dist)
  File "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 2727, in <lambda>
    add_activation_listener(lambda dist: dist.activate())
  File "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 2227, in activate
    self.insert_on(path)
  File "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 2334, in insert_on
    self.check_version_conflict()
  File "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 2373, in check_version_conflict
    for modname in self._get_metadata('top_level.txt'):
  File "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 2221, in _get_metadata
    for line in self.get_metadata_lines(name):
  File "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 1209, in get_metadata_lines
    return yield_lines(self.get_metadata(name))
  File "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 1201, in get_metadata
    return self._get(self._fn(self.egg_info,name))
  File "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 1316, in _get
    stream = open(path, 'rb')
IOError: [Errno 13] Permission denied: '/usr/local/lib/python2.7/dist-packages/stevedore-1.5.0.egg-info/top_level.txt'

我已经有一段时间没有做virtualenvs了，但是上次做的时候，没有权限问题。virtualenv是最新的。虽然我可以在跟踪中的指定文件中随意使用权限，但我不想这样。有没有其他人在virtualenv上遇到过类似的问题，如果有，你是如何解决的？你知道吗

编辑

当尝试在~/venvs（Ubuntu 12.04）中创建virtualenv时出现错误，与问题开始出现之前的位置相同，因此没有安装问题。你知道吗