/usr/include/simgear/canvas/ is in libsimgear-dev 3.4.0-3.
This file is owned by root:root, with mode 0o755.
..
/usr/include/simgear/canvas/Canvas.hxx
/usr/include/simgear/canvas/CanvasEvent.hxx
/usr/include/simgear/canvas/CanvasEventManager.hxx
/usr/include/simgear/canvas/CanvasEventTypes.hxx
/usr/include/simgear/canvas/CanvasEventVisitor.hxx
/usr/include/simgear/canvas/CanvasMgr.hxx
/usr/include/simgear/canvas/CanvasObjectPlacement.hxx
/usr/include/simgear/canvas/CanvasPlacement.hxx
/usr/include/simgear/canvas/CanvasSystemAdapter.hxx
/usr/include/simgear/canvas/CanvasWindow.hxx
/usr/include/simgear/canvas/ODGauge.hxx
/usr/include/simgear/canvas/ShivaVG/
/usr/include/simgear/canvas/ShivaVG/openvg.h
/usr/include/simgear/canvas/ShivaVG/vgu.h
/usr/include/simgear/canvas/VGInitOperation.hxx
/usr/include/simgear/canvas/canvas_fwd.hxx
/usr/include/simgear/canvas/elements/
/usr/include/simgear/canvas/elements/CanvasElement.hxx
/usr/include/simgear/canvas/elements/CanvasGroup.hxx
/usr/include/simgear/canvas/elements/CanvasImage.hxx
/usr/include/simgear/canvas/elements/CanvasMap.hxx
/usr/include/simgear/canvas/elements/CanvasPath.hxx
/usr/include/simgear/canvas/elements/CanvasText.hxx
/usr/include/simgear/canvas/elements/detail/
/usr/include/simgear/canvas/elements/detail/add_segment_variadic.hxx
/usr/include/simgear/canvas/events/
/usr/include/simgear/canvas/events/CustomEvent.hxx
/usr/include/simgear/canvas/events/DeviceEvent.hxx
/usr/include/simgear/canvas/events/KeyboardEvent.hxx
/usr/include/simgear/canvas/events/MouseEvent.hxx
/usr/include/simgear/canvas/layout/
/usr/include/simgear/canvas/layout/AlignFlag_values.hxx
/usr/include/simgear/canvas/layout/BoxLayout.hxx
/usr/include/simgear/canvas/layout/Layout.hxx
/usr/include/simgear/canvas/layout/LayoutItem.hxx
/usr/include/simgear/canvas/layout/NasalWidget.hxx
/usr/include/simgear/canvas/layout/SpacerItem.hxx