title: No module named _cffi_backend
body: <p>I have Python 2.6 in my Linux rhel-5. I have installed pip and required CFFI packages. When I try to run a sample CFFI program:</p>
  <pre><code>ffi = FFI()
  </code></pre>
  <p>it says:</p>
  <pre><code>File &quot;/usr/lib/python2.6/site-packages/cffi/api.py&quot;, line 56, in __init__
      import _cffi_backend as backend
  ImportError: No module named _cffi_backend
  </code></pre>
  <p>What could be the possible error? Did I miss something during installation? I have installed pip, wheel, pycparser, pytest and cffi.</p>