/usr/include/IV-2_6/ is in ivtools-dev 1.2.11a1-6.
This file is owned by root:root, with mode 0o755.
..
/usr/include/IV-2_6/InterViews/
/usr/include/IV-2_6/InterViews/adjuster.h
/usr/include/IV-2_6/InterViews/alignment.h
/usr/include/IV-2_6/InterViews/banner.h
/usr/include/IV-2_6/InterViews/border.h
/usr/include/IV-2_6/InterViews/box.h
/usr/include/IV-2_6/InterViews/button.h
/usr/include/IV-2_6/InterViews/compeditor.h
/usr/include/IV-2_6/InterViews/control.h
/usr/include/IV-2_6/InterViews/deck.h
/usr/include/IV-2_6/InterViews/defs.h
/usr/include/IV-2_6/InterViews/dialog.h
/usr/include/IV-2_6/InterViews/filebrowser.h
/usr/include/IV-2_6/InterViews/filechooser.h
/usr/include/IV-2_6/InterViews/frame.h
/usr/include/IV-2_6/InterViews/glue.h
/usr/include/IV-2_6/InterViews/ihandler.h
/usr/include/IV-2_6/InterViews/interactor.h
/usr/include/IV-2_6/InterViews/iwindow.h
/usr/include/IV-2_6/InterViews/matcheditor.h
/usr/include/IV-2_6/InterViews/menu.h
/usr/include/IV-2_6/InterViews/message.h
/usr/include/IV-2_6/InterViews/minmax.h
/usr/include/IV-2_6/InterViews/paint.h
/usr/include/IV-2_6/InterViews/painter.h
/usr/include/IV-2_6/InterViews/panner.h
/usr/include/IV-2_6/InterViews/perspective.h
/usr/include/IV-2_6/InterViews/rubband.h
/usr/include/IV-2_6/InterViews/rubcurve.h
/usr/include/IV-2_6/InterViews/rubgroup.h
/usr/include/IV-2_6/InterViews/rubline.h
/usr/include/IV-2_6/InterViews/rubrect.h
/usr/include/IV-2_6/InterViews/rubverts.h
/usr/include/IV-2_6/InterViews/scene.h
/usr/include/IV-2_6/InterViews/scrollbar.h
/usr/include/IV-2_6/InterViews/scroller.h
/usr/include/IV-2_6/InterViews/sensor.h
/usr/include/IV-2_6/InterViews/shape.h
/usr/include/IV-2_6/InterViews/strbrowser.h
/usr/include/IV-2_6/InterViews/strchooser.h
/usr/include/IV-2_6/InterViews/streditor.h
/usr/include/IV-2_6/InterViews/subject.h
/usr/include/IV-2_6/InterViews/textbuffer.h
/usr/include/IV-2_6/InterViews/textdisplay.h
/usr/include/IV-2_6/InterViews/texteditor.h
/usr/include/IV-2_6/InterViews/textstyle.h
/usr/include/IV-2_6/InterViews/tray.h
/usr/include/IV-2_6/InterViews/viewport.h
/usr/include/IV-2_6/InterViews/world.h
/usr/include/IV-2_6/_enter.h
/usr/include/IV-2_6/_leave.h
/usr/include/IV-2_6/_names.h