我尝试重新创建virtualenv：

foo_bar_d@aptguettler:~$ virtualenv --system-site-packages .

我得到这个异常：

foo_bar_d@aptguettler:~$ virtualenv --system-site-packages .
New python executable in /home/foo_bar_d/bin/python
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 711, in main
    symlink=options.symlink)
  File "/usr/local/lib/python2.7/dist-packages/virtualenv.py", line 924, in create_environment
    site_packages=site_packages, clear=clear, symlink=symlink))
  File "/usr/local/lib/python2.7/dist-packages/virtualenv.py", line 1230, in install_python
    shutil.copyfile(executable, py_executable)
  File "/usr/lib/python2.7/shutil.py", line 83, in copyfile
    with open(dst, 'wb') as fdst:
IOError: [Errno 26] Text file busy: '/home/foo_bar_d/bin/python'

有人知道为什么会发生这种异常吗？