我在一家大型公司工作，那里有一个hadoop集群。我让管理员安装了 virtualenv 在所有hadoop工作节点上，以便我可以提交 mrjob s与标准 Python 工作节点上可能不存在的依赖项。根据这里的文档，我的 mrjob.conf 文件看起来像：

runners:
  hadoop:
    setup:
    - virtualenv venv
    - . venv/bin/activate
    - pip install nltk

我有一份简单的工作 nltk 包裹。我可以验证这个安装脚本是否在工作节点上运行（我可以将一些简单的命令，如将数据写入 /tmp 它是有效的）。但是，我得到以下错误：

New python executable in venv/bin/python
Installing setuptools............done.
Installing pip...
  Error [Errno 13] Permission denied while executing command /storage5/hadoop/map...env/bin/easy_install /usr/share/python-virtualenv/pip-1.1.tar.gz
...Installing pip...done.
Traceback (most recent call last):
  File "/usr/bin/virtualenv", line 3, in <module>
    virtualenv.main()
  File "/usr/lib/python2.7/dist-packages/virtualenv.py", line 938, in main
    never_download=options.never_download)
  File "/usr/lib/python2.7/dist-packages/virtualenv.py", line 1054, in create_environment
    install_pip(py_executable, search_dirs=search_dirs, never_download=never_download)
  File "/usr/lib/python2.7/dist-packages/virtualenv.py", line 643, in install_pip
    filter_stdout=_filter_setup)
  File "/usr/lib/python2.7/dist-packages/virtualenv.py", line 976, in call_subprocess
    cwd=cwd, env=env)
  File "/usr/lib/python2.7/subprocess.py", line 679, in __init__
    errread, errwrite)
  File "/usr/lib/python2.7/subprocess.py", line 1249, in _execute_child
    raise child_exception
OSError: [Errno 13] Permission denied
java.lang.RuntimeException: PipeMapRed.waitOutputThreads(): subprocess failed with code 1
    at org.apache.hadoop.streaming.PipeMapRed.waitOutputThreads(PipeMapRed.java:362)
    at org.apache.hadoop.streaming.PipeMapRed.mapRedFinished(PipeMapRed.java:572)
    at org.apache.hadoop.streaming.PipeMapper.close(PipeMapper.java:136)
    at org.apache.hadoop.mapred.MapRunner.run(MapRunner.java:57)
    at org.apache.hadoop.streaming.PipeMapRunner.run(PipeMapRunner.java:34)
    at org.apache.hadoop.mapred.MapTask.runOldMapper(MapTask.java:417)
    at org.apache.hadoop.mapred.MapTask.run(MapTask.java:332)
    at org.apache.hadoop.mapred.Child$4.run(Child.java:268)
    at java.security.AccessController.doPrivileged(Native Method)
    at javax.security.auth.Subject.doAs(Subject.java:396)
    at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1438)
    at org.apache.hadoop.mapred.Child.main(Child.java:262)

是什么导致了这个错误？