No.  PyNaCl 0.2.3 always raises this warning:
```Bash
>>> import nacl.signing
/home/vlad/projects/virtualenv/devel/local/lib/python2.7/site-packages/cffi/vengine_cpy.py:166: UserWarning: reimporting '_cffi__x1023bcbxbd030567' might overwrite older definitions
  % (self.verifier.get_module_name()))
```