title: Exception: Version mismatch:cffi
body: <p>I'm trying to install scrapy using</p>
  
  <pre><code>pip install Scrapy
  </code></pre>
  
  <p>But I'm getting this error:</p>
  
  <pre><code>    Exception: Version mismatch: this is the 'cffi' package version 1.10.0, located in '/usr/local/lib/python2.7/dist-packages/cffi/api.pyc'.
      When we import the top-level '_cffi_backend' extension module, we get version 1.5.2, located in '/usr/lib/python2.7/dist-packages/_cffi_backend.x86_64-linux-gnu.so'.  
      The two versions should be equal; check your installation.
  </code></pre>
  
  <p>Tried installing the dependencies:</p>
  
  <pre><code>sudo apt-get install build-essential libssl-dev libffi-dev python-dev
  </code></pre>
  
  <p>Still the same error.</p>
  
  <p>can anyone tell me what I'm missing ?</p>
  
  <p>I'm on ubuntu 16.04</p>