/usr/include/python2.7_d/sip.h is in python-sip-dev 4.16.4+dfsg-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/include/python2.7_d/../python2.7/sip.h
/usr/include/python2.7_d/../python2.7/sip.h