/usr/share/gtk-doc/html/libgnomeprint is in libgnomeprint2.2-doc 2.18.8-3ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/gtk-doc/html/../../doc/libgnomeprint2.2-doc/html
/usr/share/gtk-doc/html/../../doc/libgnomeprint2.2-doc/html