/usr/include/libgnome-2.0/libgnome/ is in libgnome2-dev 2.32.1-2ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/libgnome-2.0/libgnome/gnome-config.h
/usr/include/libgnome-2.0/libgnome/gnome-exec.h
/usr/include/libgnome-2.0/libgnome/gnome-gconf.h
/usr/include/libgnome-2.0/libgnome/gnome-help.h
/usr/include/libgnome-2.0/libgnome/gnome-i18n.h
/usr/include/libgnome-2.0/libgnome/gnome-init.h
/usr/include/libgnome-2.0/libgnome/gnome-macros.h
/usr/include/libgnome-2.0/libgnome/gnome-program.h
/usr/include/libgnome-2.0/libgnome/gnome-score.h
/usr/include/libgnome-2.0/libgnome/gnome-sound.h
/usr/include/libgnome-2.0/libgnome/gnome-triggers.h
/usr/include/libgnome-2.0/libgnome/gnome-url.h
/usr/include/libgnome-2.0/libgnome/gnome-util.h
/usr/include/libgnome-2.0/libgnome/libgnome.h
/usr/include/libgnome-2.0/libgnome/libgnometypebuiltins.h