/usr/include/ClanLib-1.0/ClanLib/Signals/ is in libclanlib-dev 1.0~svn3827-3+b4.
This file is owned by root:root, with mode 0o755.
..
/usr/include/ClanLib-1.0/ClanLib/Signals/signal.h
/usr/include/ClanLib-1.0/ClanLib/Signals/signal_v0.h
/usr/include/ClanLib-1.0/ClanLib/Signals/signal_v1.h
/usr/include/ClanLib-1.0/ClanLib/Signals/signal_v2.h
/usr/include/ClanLib-1.0/ClanLib/Signals/signal_v3.h
/usr/include/ClanLib-1.0/ClanLib/Signals/signal_v4.h
/usr/include/ClanLib-1.0/ClanLib/Signals/signal_v5.h
/usr/include/ClanLib-1.0/ClanLib/Signals/slot.h
/usr/include/ClanLib-1.0/ClanLib/Signals/slot_container.h
/usr/include/ClanLib-1.0/ClanLib/Signals/slot_generic.h
/usr/include/ClanLib-1.0/ClanLib/Signals/slot_v0.h
/usr/include/ClanLib-1.0/ClanLib/Signals/slot_v1.h
/usr/include/ClanLib-1.0/ClanLib/Signals/slot_v2.h
/usr/include/ClanLib-1.0/ClanLib/Signals/slot_v3.h
/usr/include/ClanLib-1.0/ClanLib/Signals/slot_v4.h
/usr/include/ClanLib-1.0/ClanLib/Signals/slot_v5.h
/usr/include/ClanLib-1.0/ClanLib/Signals/slotbuffer_v0.h
/usr/include/ClanLib-1.0/ClanLib/Signals/slotbuffer_v1.h