/usr/include/boost/detail/winapi/ is in libboost1.65-dev 1.65.1+dfsg-0ubuntu5.
This file is owned by root:root, with mode 0o755.
..
/usr/include/boost/detail/winapi/GetCurrentProcess.hpp
/usr/include/boost/detail/winapi/GetCurrentThread.hpp
/usr/include/boost/detail/winapi/GetLastError.hpp
/usr/include/boost/detail/winapi/GetProcessTimes.hpp
/usr/include/boost/detail/winapi/GetThreadTimes.hpp
/usr/include/boost/detail/winapi/access_rights.hpp
/usr/include/boost/detail/winapi/apc.hpp
/usr/include/boost/detail/winapi/basic_types.hpp
/usr/include/boost/detail/winapi/character_code_conversion.hpp
/usr/include/boost/detail/winapi/condition_variable.hpp
/usr/include/boost/detail/winapi/config.hpp
/usr/include/boost/detail/winapi/critical_section.hpp
/usr/include/boost/detail/winapi/crypt.hpp
/usr/include/boost/detail/winapi/dbghelp.hpp
/usr/include/boost/detail/winapi/debugapi.hpp
/usr/include/boost/detail/winapi/detail/
/usr/include/boost/detail/winapi/detail/cast_ptr.hpp
/usr/include/boost/detail/winapi/directory_management.hpp
/usr/include/boost/detail/winapi/dll.hpp
/usr/include/boost/detail/winapi/environment.hpp
/usr/include/boost/detail/winapi/error_codes.hpp
/usr/include/boost/detail/winapi/error_handling.hpp
/usr/include/boost/detail/winapi/event.hpp
/usr/include/boost/detail/winapi/file_management.hpp
/usr/include/boost/detail/winapi/file_mapping.hpp
/usr/include/boost/detail/winapi/get_current_process.hpp
/usr/include/boost/detail/winapi/get_current_process_id.hpp
/usr/include/boost/detail/winapi/get_current_thread.hpp
/usr/include/boost/detail/winapi/get_current_thread_id.hpp
/usr/include/boost/detail/winapi/get_last_error.hpp
/usr/include/boost/detail/winapi/get_process_times.hpp
/usr/include/boost/detail/winapi/get_system_directory.hpp
/usr/include/boost/detail/winapi/get_thread_times.hpp
/usr/include/boost/detail/winapi/handle_info.hpp
/usr/include/boost/detail/winapi/handles.hpp
/usr/include/boost/detail/winapi/heap_memory.hpp
/usr/include/boost/detail/winapi/init_once.hpp
/usr/include/boost/detail/winapi/jobs.hpp
/usr/include/boost/detail/winapi/limits.hpp
/usr/include/boost/detail/winapi/local_memory.hpp
/usr/include/boost/detail/winapi/memory.hpp
/usr/include/boost/detail/winapi/mutex.hpp
/usr/include/boost/detail/winapi/overlapped.hpp
/usr/include/boost/detail/winapi/page_protection_flags.hpp
/usr/include/boost/detail/winapi/pipes.hpp
/usr/include/boost/detail/winapi/priority_class.hpp
/usr/include/boost/detail/winapi/process.hpp
/usr/include/boost/detail/winapi/security.hpp
/usr/include/boost/detail/winapi/semaphore.hpp
/usr/include/boost/detail/winapi/shell.hpp
/usr/include/boost/detail/winapi/show_window.hpp
/usr/include/boost/detail/winapi/srw_lock.hpp
/usr/include/boost/detail/winapi/stack_backtrace.hpp
/usr/include/boost/detail/winapi/synchronization.hpp
/usr/include/boost/detail/winapi/system.hpp
/usr/include/boost/detail/winapi/thread.hpp
/usr/include/boost/detail/winapi/thread_pool.hpp
/usr/include/boost/detail/winapi/time.hpp
/usr/include/boost/detail/winapi/timers.hpp
/usr/include/boost/detail/winapi/tls.hpp
/usr/include/boost/detail/winapi/wait.hpp
/usr/include/boost/detail/winapi/waitable_timer.hpp