/usr/include/boost/fiber/ is in libboost1.62-dev 1.62.0+dfsg-5.
This file is owned by root:root, with mode 0o755.
..
/usr/include/boost/fiber/algo/
/usr/include/boost/fiber/algo/algorithm.hpp
/usr/include/boost/fiber/algo/detail/
/usr/include/boost/fiber/algo/detail/chase_lev_queue.hpp
/usr/include/boost/fiber/algo/round_robin.hpp
/usr/include/boost/fiber/algo/shared_work.hpp
/usr/include/boost/fiber/all.hpp
/usr/include/boost/fiber/barrier.hpp
/usr/include/boost/fiber/bounded_channel.hpp
/usr/include/boost/fiber/channel_op_status.hpp
/usr/include/boost/fiber/condition_variable.hpp
/usr/include/boost/fiber/context.hpp
/usr/include/boost/fiber/detail/
/usr/include/boost/fiber/detail/config.hpp
/usr/include/boost/fiber/detail/convert.hpp
/usr/include/boost/fiber/detail/data.hpp
/usr/include/boost/fiber/detail/decay_copy.hpp
/usr/include/boost/fiber/detail/disable_overload.hpp
/usr/include/boost/fiber/detail/fss.hpp
/usr/include/boost/fiber/detail/spinlock.hpp
/usr/include/boost/fiber/detail/wrap.hpp
/usr/include/boost/fiber/exceptions.hpp
/usr/include/boost/fiber/fiber.hpp
/usr/include/boost/fiber/fixedsize_stack.hpp
/usr/include/boost/fiber/fss.hpp
/usr/include/boost/fiber/future/
/usr/include/boost/fiber/future.hpp
/usr/include/boost/fiber/future/async.hpp
/usr/include/boost/fiber/future/detail/
/usr/include/boost/fiber/future/detail/shared_state.hpp
/usr/include/boost/fiber/future/detail/shared_state_object.hpp
/usr/include/boost/fiber/future/detail/task_base.hpp
/usr/include/boost/fiber/future/detail/task_object.hpp
/usr/include/boost/fiber/future/future.hpp
/usr/include/boost/fiber/future/future_status.hpp
/usr/include/boost/fiber/future/packaged_task.hpp
/usr/include/boost/fiber/future/promise.hpp
/usr/include/boost/fiber/mutex.hpp
/usr/include/boost/fiber/operations.hpp
/usr/include/boost/fiber/policy.hpp
/usr/include/boost/fiber/pooled_fixedsize_stack.hpp
/usr/include/boost/fiber/properties.hpp
/usr/include/boost/fiber/protected_fixedsize_stack.hpp
/usr/include/boost/fiber/recursive_mutex.hpp
/usr/include/boost/fiber/recursive_timed_mutex.hpp
/usr/include/boost/fiber/scheduler.hpp
/usr/include/boost/fiber/segmented_stack.hpp
/usr/include/boost/fiber/timed_mutex.hpp
/usr/include/boost/fiber/type.hpp
/usr/include/boost/fiber/unbounded_channel.hpp