/usr/include/msgpack/preprocessor/facilities/ is in libmsgpack-dev 2.1.5-1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/msgpack/preprocessor/facilities/apply.hpp
/usr/include/msgpack/preprocessor/facilities/detail/
/usr/include/msgpack/preprocessor/facilities/detail/is_empty.hpp
/usr/include/msgpack/preprocessor/facilities/empty.hpp
/usr/include/msgpack/preprocessor/facilities/expand.hpp
/usr/include/msgpack/preprocessor/facilities/identity.hpp
/usr/include/msgpack/preprocessor/facilities/intercept.hpp
/usr/include/msgpack/preprocessor/facilities/is_1.hpp
/usr/include/msgpack/preprocessor/facilities/is_empty.hpp
/usr/include/msgpack/preprocessor/facilities/is_empty_or_1.hpp
/usr/include/msgpack/preprocessor/facilities/is_empty_variadic.hpp
/usr/include/msgpack/preprocessor/facilities/overload.hpp