https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108210
--- Comment #7 from Jonathan Wakely <redi at gcc dot gnu.org> --- Probably a dup of PR 108225 i.e. expecting --enable-threads=win32 to provide std::mutex without _WIN32_WINNT >= 0x0600 But it isn't provided, because the win32 model doesn't support C++11 threading for ancient versions: /* Condition variables are supported on Vista and Server 2008 or later. */
