/usr/lib/pyshared/python2.7/sklearn/ensemble/_gradient_boosting.so is in python-sklearn-lib 0.14.1-2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/pyshared/python2.7/sklearn/ensemble/../../../../python2.7/dist-packages/sklearn/ensemble/_gradient_boosting.so