title: sklearn ImportError: No module named _check_build
body: <p>I'm trying to import sklearn, however when I attempt to do so I receive the following:</p>
  
  <pre><code>---------------------------------------------------------------------------
  ImportError                               Traceback (most recent call last)
  &lt;ipython-input-2-8fd979e02004&gt; in &lt;module&gt;()
  ----&gt; 1 import sklearn
  
  C:\Users\Alpine\AppData\Local\Enthought\Canopy\User\sklearn\__init__.py in &lt;module&gt;()
       29     # process, as it may not be compiled yet
       30 else:
  ---&gt; 31     from . import __check_build
       32     from .base import clone
       33 
  
  C:\Users\Alpine\AppData\Local\Enthought\Canopy\User\sklearn\__check_build\__init__.py in &lt;module&gt;()
       44     from ._check_build import check_build
       45 except ImportError as e:
  ---&gt; 46     raise_build_error(e)
  
  C:\Users\Alpine\AppData\Local\Enthought\Canopy\User\sklearn\__check_build\__init__.py in raise_build_error(e)
       39 to build the package before using it: run `python setup.py install` or
       40 `make` in the source directory.
  ---&gt; 41 %s""" % (e, local_dir, ''.join(dir_content).strip(), msg))
       42 
       43 try:
  
  ImportError: No module named _check_build
  ___________________________________________________________________________
  Contents of C:\Users\Alpine\AppData\Local\Enthought\Canopy\User\sklearn\__check_build:
  setup.py                  setup.pyc                 _check_build.c
  _check_build.pyx          __init__.py               __init__.pyc
  ___________________________________________________________________________
  It seems that scikit-learn has not been built correctly.
  
  If you have installed scikit-learn from source, please do not forget
  to build the package before using it: run `python setup.py install` or
  `make` in the source directory.
  
  If you have used an installer, please check that it is suited for your
  Python version, your operating system and your platform.
  
  ERROR: An unexpected error occurred while tokenizing input
  The following traceback may be corrupted or invalid
  The error message is: ('EOF in multi-line string', (1, 2))
  </code></pre>
  
  <p>I'm fairly sure that scikit-learn <a href="http://scikit-learn.org/stable/install.html" rel="noreferrer">has been correctly built</a> as I managed to run <code>python setup.py install</code> without any incident. I did however try running <code>python setup.py bdist_wininst -b doc/logos/scikit-learn-logo.bmp</code> though was interrupted at <code>error: cannot copy tree 'build\scripts.win-amd64-2.7': not a directory</code>.</p>
  
  <p>Might anybody have an idea on how to fix this?</p>