importorror：没有名为extern的模块；

Question

我正试着安装燃料和燃料块

pip install git+git://github.com/mila-udem/blocks.git@v0.0.1                        
pip install git+git://github.com/mila-udem/fuel.git@v0.0.1

（我使用的是根帐户） 然后我遇到了问题

pip install git+git://github.com/mila-udem/fuel.git@v0.0.1                       
Downloading/unpacking git+git://github.com/mila-udem/fuel.git@v0.0.1   
Cloning git://github.com/mila-udem/fuel.git to /tmp/pip-PnqUs3-build
Running setup.py (path:/tmp/pip-PnqUs3-build/setup.py) egg_info for package from git+git://github.com/mila-udem/fuel.git                                          
    Traceback (most recent call last):                                               
      File "<string>", line 3, in <module>                                         
      File "build/bdist.linux-x86_64/egg/setuptools/__init__.py", line 11, in <module>                                                                     
      File "build/bdist.linux-x86_64/egg/setuptools/extern/__init__.py", line 1, in  <module>                                                                
    ImportError: No module named extern                                            
    Complete output from command python setup.py egg_info:

Traceback (most recent call last):

  File "", line 3, in <module>

  File "build/bdist.linux-x86_64/egg/setuptools/__init__.py", line 11, in <module>

  File "build/bdist.linux-x86_64/egg/setuptools/extern/__init__.py", line 1, in <module>

ImportError: No module named extern

----------------------------------------
Cleaning up...

我试图重新安装/更新安装工具，但仍然无法正常工作。谢谢。