/usr/include/gnome-disk-utility/gdu/ is in libgdu-dev 3.0.2-2ubuntu7.
This file is owned by root:root, with mode 0o755.
..
/usr/include/gnome-disk-utility/gdu/gdu-adapter.h
/usr/include/gnome-disk-utility/gdu/gdu-callbacks.h
/usr/include/gnome-disk-utility/gdu/gdu-device.h
/usr/include/gnome-disk-utility/gdu/gdu-drive.h
/usr/include/gnome-disk-utility/gdu/gdu-error.h
/usr/include/gnome-disk-utility/gdu/gdu-expander.h
/usr/include/gnome-disk-utility/gdu/gdu-hub.h
/usr/include/gnome-disk-utility/gdu/gdu-known-filesystem.h
/usr/include/gnome-disk-utility/gdu/gdu-linux-lvm2-volume-group.h
/usr/include/gnome-disk-utility/gdu/gdu-linux-lvm2-volume-hole.h
/usr/include/gnome-disk-utility/gdu/gdu-linux-lvm2-volume.h
/usr/include/gnome-disk-utility/gdu/gdu-linux-md-drive.h
/usr/include/gnome-disk-utility/gdu/gdu-machine.h
/usr/include/gnome-disk-utility/gdu/gdu-pool.h
/usr/include/gnome-disk-utility/gdu/gdu-port.h
/usr/include/gnome-disk-utility/gdu/gdu-presentable.h
/usr/include/gnome-disk-utility/gdu/gdu-process.h
/usr/include/gnome-disk-utility/gdu/gdu-types.h
/usr/include/gnome-disk-utility/gdu/gdu-util.h
/usr/include/gnome-disk-utility/gdu/gdu-volume-hole.h
/usr/include/gnome-disk-utility/gdu/gdu-volume.h
/usr/include/gnome-disk-utility/gdu/gdu.h