/usr/share/gtk-doc/html/libgnomecanvas is in libgnomecanvas2-doc 2.30.3-2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/gtk-doc/html/../../doc/libgnomecanvas2-doc/html
/usr/share/gtk-doc/html/../../doc/libgnomecanvas2-doc/html