/usr/include/ is in libmemcached-dev 0.44-1.1build1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/libmemcached/
/usr/include/libmemcached/allocators.h
/usr/include/libmemcached/analyze.h
/usr/include/libmemcached/auto.h
/usr/include/libmemcached/behavior.h
/usr/include/libmemcached/callback.h
/usr/include/libmemcached/configure.h
/usr/include/libmemcached/constants.h
/usr/include/libmemcached/delete.h
/usr/include/libmemcached/dump.h
/usr/include/libmemcached/exception.hpp
/usr/include/libmemcached/fetch.h
/usr/include/libmemcached/flush.h
/usr/include/libmemcached/flush_buffers.h
/usr/include/libmemcached/get.h
/usr/include/libmemcached/hash.h
/usr/include/libmemcached/memcached/
/usr/include/libmemcached/memcached/protocol_binary.h
/usr/include/libmemcached/memcached.h
/usr/include/libmemcached/memcached.hpp
/usr/include/libmemcached/memcached_util.h
/usr/include/libmemcached/parse.h
/usr/include/libmemcached/platform.h
/usr/include/libmemcached/protocol/
/usr/include/libmemcached/protocol/cache.h
/usr/include/libmemcached/protocol/callback.h
/usr/include/libmemcached/protocol_handler.h
/usr/include/libmemcached/quit.h
/usr/include/libmemcached/result.h
/usr/include/libmemcached/sasl.h
/usr/include/libmemcached/server.h
/usr/include/libmemcached/server_list.h
/usr/include/libmemcached/stats.h
/usr/include/libmemcached/storage.h
/usr/include/libmemcached/strerror.h
/usr/include/libmemcached/string.h
/usr/include/libmemcached/types.h
/usr/include/libmemcached/util/
/usr/include/libmemcached/util/ping.h
/usr/include/libmemcached/util/pool.h
/usr/include/libmemcached/util/version.h
/usr/include/libmemcached/util.h
/usr/include/libmemcached/verbosity.h
/usr/include/libmemcached/version.h
/usr/include/libmemcached/visibility.h
/usr/include/libmemcached/watchpoint.h
/usr/include/libhashkit/
/usr/include/libhashkit/algorithm.h
/usr/include/libhashkit/behavior.h
/usr/include/libhashkit/configure.h
/usr/include/libhashkit/digest.h
/usr/include/libhashkit/function.h
/usr/include/libhashkit/hashkit.h
/usr/include/libhashkit/strerror.h
/usr/include/libhashkit/types.h
/usr/include/libhashkit/visibility.h