id summary reporter owner description type status milestone component version severity resolution keywords cc 7081 WinError.h capitalization in boost/detail/win/basic_types.hpp Isaac Dupree viboes "If #include were lowercased to #include , it would be possible to cross-compile from Linux to Windows using MinGW (and Windows would still be fine because Windows is case-insensitive). A similar change was made to asio in #4491 . In boost/detail/win/basic_types.hpp . This affects at least programs that use Boost.Chrono." Bugs closed Boost 1.51.0 chrono Boost 1.50.0 Problem fixed