title: building lib with pybind11 linking other shared lib
body: <p>My project reply on a SO file which I will make it by <code>cmake</code> installing under my project folder.And it works files when I run <code>python setup.py install</code></p>
  
  <p>But I install it by pip, because pip will copy the project into a tmpfile,It will be removed after installed and the SO file also be removed. Hence, when I import my project, it fails for not finding the SO file.</p>
  
  <p>Of course, I can install the SO file to <code>/usr/local/lib</code>, but I don't want to</p>
  
  <p>Anyone has idea to solve it?</p>