I just met a weird import problem of supervisor as below:

```
:~# /usr/local/bin/supervisorctl status
Traceback (most recent call last):
  File "/usr/local/bin/supervisorctl", line 7, in <module>
    from supervisor.supervisorctl import main
  File "/usr/local/lib/python2.7/dist-packages/supervisor/supervisorctl.py", line 36, in <module>
    from supervisor.options import ClientOptions
  File "/usr/local/lib/python2.7/dist-packages/supervisor/options.py", line 23, in <module>
    from supervisor.datatypes import process_or_group_name
ImportError: cannot import name process_or_group_name

```

Then I tried to run this with ipython:

```
---------------------------------------------------------------------------
ImportError                               Traceback (most recent call last)
/usr/lib/python2.7/dist-packages/IPython/utils/py3compat.pyc in execfile(fname, *where)
    202             else:
    203                 filename = fname
--> 204             __builtin__.execfile(filename, *where)

/usr/local/lib/python2.7/dist-packages/supervisor/options.py in <module>()
     24 from supervisor.medusa import asyncore_25 as asyncore
     25
---> 26 from supervisor.datatypes import process_or_group_name
     27 from supervisor.datatypes import boolean
     28 from supervisor.datatypes import integer

ImportError: cannot import name process_or_group_name
> /usr/local/lib/python2.7/dist-packages/supervisor/options.py(26)<module>()
     25
---> 26 from supervisor.datatypes import process_or_group_name
     27 from supervisor.datatypes import boolean

ipdb> supervisor.datatypes.__file__
'/usr/lib/python2.7/dist-packages/supervisor/datatypes.pyc'
ipdb> sys.path
['/usr/local/lib/python2.7/dist-packages/supervisor', '', '/usr/bin', '/usr/lib/python2.7', '/usr/lib/python2.7/plat-x86_64-linux-gnu', '/usr/lib/python2.7/lib-tk', '/usr/lib/python2.7/lib-old', '/usr/lib/python2.7/lib-dynload', '/usr/local/lib/python2.7/dist-packages', '/usr/lib/python2.7/dist-packages', '/usr/lib/python2.7/dist-packages/IPython/extensions']

```

The weird part is sys.path says 

```
'/usr/local/lib/python2.7/dist-packages' 

```

prior 

```
'/usr/lib/python2.7/dist-packages'

```

but the program is actually using 

```
'/usr/lib/python2.7/dist-packages/supervisor/datatypes.pyc'

```

instead of 

```
'/usr/local/lib/python2.7/dist-packages/supervisor/datatypes.pyc'

```

which result in this problem, I really don't understand.