/usr/include/msgpack/preprocessor/array/ is in libmsgpack-dev 2.1.5-1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/msgpack/preprocessor/array/data.hpp
/usr/include/msgpack/preprocessor/array/detail/
/usr/include/msgpack/preprocessor/array/detail/get_data.hpp
/usr/include/msgpack/preprocessor/array/elem.hpp
/usr/include/msgpack/preprocessor/array/enum.hpp
/usr/include/msgpack/preprocessor/array/insert.hpp
/usr/include/msgpack/preprocessor/array/pop_back.hpp
/usr/include/msgpack/preprocessor/array/pop_front.hpp
/usr/include/msgpack/preprocessor/array/push_back.hpp
/usr/include/msgpack/preprocessor/array/push_front.hpp
/usr/include/msgpack/preprocessor/array/remove.hpp
/usr/include/msgpack/preprocessor/array/replace.hpp
/usr/include/msgpack/preprocessor/array/reverse.hpp
/usr/include/msgpack/preprocessor/array/size.hpp
/usr/include/msgpack/preprocessor/array/to_list.hpp
/usr/include/msgpack/preprocessor/array/to_seq.hpp
/usr/include/msgpack/preprocessor/array/to_tuple.hpp