jamesob commented on this pull request.
> @@ -759,8 +759,21 @@ AC_LINK_IFELSE([AC_LANG_SOURCE([
— AC_DEFINE(HAVE_THREAD_LOCAL,1,[Define if thread_local is supported.])
+ case $host in
+ # mingw32’s implementation of thread_local has also been shown to behave
+ # erroneously under concurrent usage; see:
+ # https://gist.github.com/jamesob/fe9a872051a88b2025b1aa37bfa98605