/usr/share/gtk-doc/ is in libgnet-dev 2.0.8-2.2ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/gtk-doc/html/
/usr/share/gtk-doc/html/gnet/
/usr/share/gtk-doc/html/gnet/gnet-base64.html
/usr/share/gtk-doc/html/gnet/gnet-conn-http.html
/usr/share/gtk-doc/html/gnet/gnet-conn.html
/usr/share/gtk-doc/html/gnet/gnet-developers-async.html
/usr/share/gtk-doc/html/gnet/gnet-developers-tips.html
/usr/share/gtk-doc/html/gnet/gnet-developers.html
/usr/share/gtk-doc/html/gnet/gnet-examples-other.html
/usr/share/gtk-doc/html/gnet/gnet-examples.html
/usr/share/gtk-doc/html/gnet/gnet-gnet.html
/usr/share/gtk-doc/html/gnet/gnet-inetaddr.html
/usr/share/gtk-doc/html/gnet/gnet-iochannel.html
/usr/share/gtk-doc/html/gnet/gnet-ipv6.html
/usr/share/gtk-doc/html/gnet/gnet-mcast.html
/usr/share/gtk-doc/html/gnet/gnet-md5.html
/usr/share/gtk-doc/html/gnet/gnet-overview.html
/usr/share/gtk-doc/html/gnet/gnet-pack.html
/usr/share/gtk-doc/html/gnet/gnet-server.html
/usr/share/gtk-doc/html/gnet/gnet-sha.html
/usr/share/gtk-doc/html/gnet/gnet-socks.html
/usr/share/gtk-doc/html/gnet/gnet-tcp.html
/usr/share/gtk-doc/html/gnet/gnet-udp.html
/usr/share/gtk-doc/html/gnet/gnet-unix.html
/usr/share/gtk-doc/html/gnet/gnet-uri.html
/usr/share/gtk-doc/html/gnet/gnet.devhelp
/usr/share/gtk-doc/html/gnet/gnet.devhelp2
/usr/share/gtk-doc/html/gnet/home.png
/usr/share/gtk-doc/html/gnet/index.html
/usr/share/gtk-doc/html/gnet/index.sgml
/usr/share/gtk-doc/html/gnet/left.png
/usr/share/gtk-doc/html/gnet/libgnet-reference.html
/usr/share/gtk-doc/html/gnet/right.png
/usr/share/gtk-doc/html/gnet/style.css
/usr/share/gtk-doc/html/gnet/up.png