/usr/include/libgnomeui-2.0/libgnomeui/ is in libgnomeui-dev 2.24.5-2ubuntu2.
This file is owned by root:root, with mode 0o755.
..
/usr/include/libgnomeui-2.0/libgnomeui/gnome-about.h
/usr/include/libgnomeui-2.0/libgnomeui/gnome-app-helper.h
/usr/include/libgnomeui-2.0/libgnomeui/gnome-app-util.h
/usr/include/libgnomeui-2.0/libgnomeui/gnome-app.h
/usr/include/libgnomeui-2.0/libgnomeui/gnome-appbar.h
/usr/include/libgnomeui-2.0/libgnomeui/gnome-authentication-manager.h
/usr/include/libgnomeui-2.0/libgnomeui/gnome-client.h
/usr/include/libgnomeui-2.0/libgnomeui/gnome-color-picker.h
/usr/include/libgnomeui-2.0/libgnomeui/gnome-dateedit.h
/usr/include/libgnomeui-2.0/libgnomeui/gnome-dialog-util.h
/usr/include/libgnomeui-2.0/libgnomeui/gnome-dialog.h
/usr/include/libgnomeui-2.0/libgnomeui/gnome-druid-page-edge.h
/usr/include/libgnomeui-2.0/libgnomeui/gnome-druid-page-standard.h
/usr/include/libgnomeui-2.0/libgnomeui/gnome-druid-page.h
/usr/include/libgnomeui-2.0/libgnomeui/gnome-druid.h
/usr/include/libgnomeui-2.0/libgnomeui/gnome-entry.h
/usr/include/libgnomeui-2.0/libgnomeui/gnome-file-entry.h
/usr/include/libgnomeui-2.0/libgnomeui/gnome-font-picker.h
/usr/include/libgnomeui-2.0/libgnomeui/gnome-help.h
/usr/include/libgnomeui-2.0/libgnomeui/gnome-href.h
/usr/include/libgnomeui-2.0/libgnomeui/gnome-ice.h
/usr/include/libgnomeui-2.0/libgnomeui/gnome-icon-entry.h
/usr/include/libgnomeui-2.0/libgnomeui/gnome-icon-item.h
/usr/include/libgnomeui-2.0/libgnomeui/gnome-icon-list.h
/usr/include/libgnomeui-2.0/libgnomeui/gnome-icon-lookup.h
/usr/include/libgnomeui-2.0/libgnomeui/gnome-icon-sel.h
/usr/include/libgnomeui-2.0/libgnomeui/gnome-icon-theme.h
/usr/include/libgnomeui-2.0/libgnomeui/gnome-mdi-child.h
/usr/include/libgnomeui-2.0/libgnomeui/gnome-mdi-generic-child.h
/usr/include/libgnomeui-2.0/libgnomeui/gnome-mdi-session.h
/usr/include/libgnomeui-2.0/libgnomeui/gnome-mdi.h
/usr/include/libgnomeui-2.0/libgnomeui/gnome-messagebox.h
/usr/include/libgnomeui-2.0/libgnomeui/gnome-password-dialog.h
/usr/include/libgnomeui-2.0/libgnomeui/gnome-pixmap-entry.h
/usr/include/libgnomeui-2.0/libgnomeui/gnome-pixmap.h
/usr/include/libgnomeui-2.0/libgnomeui/gnome-popup-menu.h
/usr/include/libgnomeui-2.0/libgnomeui/gnome-propertybox.h
/usr/include/libgnomeui-2.0/libgnomeui/gnome-scores.h
/usr/include/libgnomeui-2.0/libgnomeui/gnome-stock-icons.h
/usr/include/libgnomeui-2.0/libgnomeui/gnome-theme-parser.h
/usr/include/libgnomeui-2.0/libgnomeui/gnome-thumbnail.h
/usr/include/libgnomeui-2.0/libgnomeui/gnome-types.h
/usr/include/libgnomeui-2.0/libgnomeui/gnome-ui-init.h
/usr/include/libgnomeui-2.0/libgnomeui/gnome-uidefs.h
/usr/include/libgnomeui-2.0/libgnomeui/gnome-url.h
/usr/include/libgnomeui-2.0/libgnomeui/gnome-vfs-util.h
/usr/include/libgnomeui-2.0/libgnomeui/gnome-window-icon.h
/usr/include/libgnomeui-2.0/libgnomeui/gnome-window.h
/usr/include/libgnomeui-2.0/libgnomeui/gnometypebuiltins.h
/usr/include/libgnomeui-2.0/libgnomeui/libgnomeui.h