title: install error thinks pythonpath is empty
body: <p>I am trying to install the scikits.nufft package <a href="https://github.com/elijahbal/scikits.nufft" rel="nofollow noreferrer">here</a>
  I download the zip file, unpack and cd to the directory. It contains a setup.py file so I run</p>
  <pre><code>python setup.py install
  </code></pre>
  <p>but it gives me the following error related to my PYTHONPATH</p>
  <pre><code>sudo python setup.py install
  sudo: unable to resolve host Lenovo
  /usr/local/lib/python2.7/dist-packages/distribute-0.6.31-py2.7.egg/setuptools/command/install_scripts.py:3: UserWarning: Module dap was already imported from None, but /usr/lib/python2.7/dist-packages is being added to sys.path
    from pkg_resources import Distribution, PathMetadata, ensure_directory
  running install
  Checking .pth file support in /usr/local/lib/python2.7/site-packages/
  /usr/bin/python -E -c pass
  TEST FAILED: /usr/local/lib/python2.7/site-packages/ does NOT support .pth files
  error: bad install directory or PYTHONPATH
  
  You are attempting to install a package to a directory that is not
  on PYTHONPATH and which Python does not read &quot;.pth&quot; files from.  The
  installation directory you specified (via --install-dir, --prefix, or
  the distutils default setting) was:
  
      /usr/local/lib/python2.7/site-packages/
  
  and your PYTHONPATH environment variable currently contains:
  
      ''
  
  Here are some of your options for correcting the problem:
  
  * You can choose a different installation directory, i.e., one that is
    on PYTHONPATH or supports .pth files
  
  * You can add the installation directory to the PYTHONPATH environment
    variable.  (It must then also be on PYTHONPATH whenever you run
    Python and want to use the package(s) you are installing.)
  
  * You can set up the installation directory to support &quot;.pth&quot; files by
    using one of the approaches described here:
  
    http://packages.python.org/distribute/easy_install.html#custom-installation-locations
  
  Please make the appropriate changes for your system and try again.
  </code></pre>
  <p>It seems to think the path is empty but when I check my path I get,</p>
  <pre><code>echo $PYTHONPATH
  /usr/local/lib/python2.7/site-packages:/home/david/PYTHON
  </code></pre>
  <p>Does anyone know why it might think the path is empty?? or have any other ideas as to what may be wrong here.
  Thanks,
  Dave</p>