/usr/include/wnckmm-1.0/ is in libwnckmm-1.0-0-dev 0.1.1-2+b2.
This file is owned by root:root, with mode 0o755.
..
/usr/include/wnckmm-1.0/wnckmm/
/usr/include/wnckmm-1.0/wnckmm.h
/usr/include/wnckmm-1.0/wnckmm/action-menu.h
/usr/include/wnckmm-1.0/wnckmm/application.h
/usr/include/wnckmm-1.0/wnckmm/class-group.h
/usr/include/wnckmm-1.0/wnckmm/init.h
/usr/include/wnckmm-1.0/wnckmm/libwnck-wrapper.h
/usr/include/wnckmm-1.0/wnckmm/pager.h
/usr/include/wnckmm-1.0/wnckmm/private/
/usr/include/wnckmm-1.0/wnckmm/private/action-menu_p.h
/usr/include/wnckmm-1.0/wnckmm/private/application_p.h
/usr/include/wnckmm-1.0/wnckmm/private/class-group_p.h
/usr/include/wnckmm-1.0/wnckmm/private/pager_p.h
/usr/include/wnckmm-1.0/wnckmm/private/screen_p.h
/usr/include/wnckmm-1.0/wnckmm/private/selector_p.h
/usr/include/wnckmm-1.0/wnckmm/private/tasklist_p.h
/usr/include/wnckmm-1.0/wnckmm/private/window_p.h
/usr/include/wnckmm-1.0/wnckmm/private/workspace_p.h
/usr/include/wnckmm-1.0/wnckmm/screen.h
/usr/include/wnckmm-1.0/wnckmm/selector.h
/usr/include/wnckmm-1.0/wnckmm/tasklist.h
/usr/include/wnckmm-1.0/wnckmm/window.h
/usr/include/wnckmm-1.0/wnckmm/workspace.h
/usr/include/wnckmm-1.0/wnckmm/wrap_init.h