/usr/lib/libgtkgl-2.0.so is in libgtkgl2.0-dev 2.0.1-2.2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/libgtkgl-2.0.so.1.0.1
/usr/lib/libgtkgl-2.0.so.1.0.1