/usr/ is in libgtkglextmm-x11-1.2-dev 1.2.0-8.
This file is owned by root:root, with mode 0o755.
..
/usr/include/gtkglextmm-1.2/gtkmm/
/usr/include/gtkglextmm-1.2/gtkmm/gl/
/usr/include/
/usr/include/gtkglextmm-1.2/
/usr/include/gtkglextmm-1.2/gdkglmm.h
/usr/include/gtkglextmm-1.2/gdkmm/
/usr/include/gtkglextmm-1.2/gdkmm/gl/
/usr/include/gtkglextmm-1.2/gdkmm/gl/config.h
/usr/include/gtkglextmm-1.2/gdkmm/gl/context.h
/usr/include/gtkglextmm-1.2/gdkmm/gl/defs.h
/usr/include/gtkglextmm-1.2/gdkmm/gl/drawable.h
/usr/include/gtkglextmm-1.2/gdkmm/gl/font.h
/usr/include/gtkglextmm-1.2/gdkmm/gl/init.h
/usr/include/gtkglextmm-1.2/gdkmm/gl/pixmap.h
/usr/include/gtkglextmm-1.2/gdkmm/gl/pixmapext.h
/usr/include/gtkglextmm-1.2/gdkmm/gl/private/
/usr/include/gtkglextmm-1.2/gdkmm/gl/private/config_p.h
/usr/include/gtkglextmm-1.2/gdkmm/gl/private/context_p.h
/usr/include/gtkglextmm-1.2/gdkmm/gl/private/drawable_p.h
/usr/include/gtkglextmm-1.2/gdkmm/gl/private/pixmap_p.h
/usr/include/gtkglextmm-1.2/gdkmm/gl/private/tokens_p.h
/usr/include/gtkglextmm-1.2/gdkmm/gl/private/window_p.h
/usr/include/gtkglextmm-1.2/gdkmm/gl/query.h
/usr/include/gtkglextmm-1.2/gdkmm/gl/tokens.h
/usr/include/gtkglextmm-1.2/gdkmm/gl/version.h
/usr/include/gtkglextmm-1.2/gdkmm/gl/window.h
/usr/include/gtkglextmm-1.2/gdkmm/gl/windowext.h
/usr/include/gtkglextmm-1.2/gdkmm/gl/wrap_init.h
/usr/include/gtkglextmm-1.2/gtkglmm.h
/usr/include/gtkglextmm-1.2/gtkmm/gl/defs.h
/usr/include/gtkglextmm-1.2/gtkmm/gl/drawingarea.h
/usr/include/gtkglextmm-1.2/gtkmm/gl/init.h
/usr/include/gtkglextmm-1.2/gtkmm/gl/version.h
/usr/include/gtkglextmm-1.2/gtkmm/gl/widget.h
/usr/lib/
/usr/lib/x86_64-linux-gnu/
/usr/lib/x86_64-linux-gnu/gtkglextmm-1.2/
/usr/lib/x86_64-linux-gnu/gtkglextmm-1.2/include/
/usr/lib/x86_64-linux-gnu/gtkglextmm-1.2/include/gdkglextmm-config.h
/usr/lib/x86_64-linux-gnu/gtkglextmm-1.2/proc/
/usr/lib/x86_64-linux-gnu/gtkglextmm-1.2/proc/m4/
/usr/lib/x86_64-linux-gnu/gtkglextmm-1.2/proc/m4/convert.m4
/usr/lib/x86_64-linux-gnu/gtkglextmm-1.2/proc/m4/convert_gdkglext.m4
/usr/lib/x86_64-linux-gnu/gtkglextmm-1.2/proc/m4/convert_gtkglext.m4
/usr/lib/x86_64-linux-gnu/libgdkglextmm-x11-1.2.a
/usr/lib/x86_64-linux-gnu/libgdkglextmm-x11-1.2.la
/usr/lib/x86_64-linux-gnu/libgtkglextmm-x11-1.2.a
/usr/lib/x86_64-linux-gnu/libgtkglextmm-x11-1.2.la
/usr/lib/x86_64-linux-gnu/pkgconfig/
/usr/lib/x86_64-linux-gnu/pkgconfig/gdkglextmm-1.2.pc
/usr/lib/x86_64-linux-gnu/pkgconfig/gdkglextmm-x11-1.2.pc
/usr/lib/x86_64-linux-gnu/pkgconfig/gtkglextmm-1.2.pc
/usr/lib/x86_64-linux-gnu/pkgconfig/gtkglextmm-x11-1.2.pc
/usr/share/
/usr/share/aclocal/
/usr/share/aclocal/gtkglextmm-1.2.m4
/usr/share/doc/
/usr/share/doc/libgtkglextmm-x11-1.2-dev/
/usr/share/doc/libgtkglextmm-x11-1.2-dev/copyright
/usr/lib/x86_64-linux-gnu/libgdkglextmm-x11-1.2.so
/usr/lib/x86_64-linux-gnu/libgtkglextmm-x11-1.2.so
/usr/share/doc/libgtkglextmm-x11-1.2-dev/changelog.Debian.gz