On Mac OS X, what should I do if I see this:

$ make install-user
python3 setup.py install --user
/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/setuptools/dist.py:285: UserWarning: Normalizing '0.2.3a' to '0.2.3a0'
  normalized_version,
running install
running bdist_egg
running egg_info
.
.
.
scrypt-1.1.6/lib/crypto/crypto_aesctr.c:38:10: fatal error: 'openssl/aes.h' file not found
#include <openssl/aes.h>
         ^
1 error generated.
error: Setup script exited with error: command '/usr/bin/clang' failed with exit status 1
make: *** [install-user] Error 1

I usually use MacPorts, but I went with the Python Release PKG 3.5.2 in this case.