I've been seeing a bunch of CI errors related to serialization that seem to be new. Not seeing this so much on the test dashboard however. https://ci.appveyor.com/project/jeking3/date-time-1evbf/builds/33988388 gcc.compile.c++ bin.v2\libs\serialization\build\gcc-mngw6\rls\cxstd-11-iso\thrd-mlt\vsblt-hdn\xml_iarchive.o gcc.compile.c++ bin.v2\libs\serialization\build\gcc-mngw6\rls\cxstd-11-iso\thrd-mlt\vsblt-hdn\xml_oarchive.o In file included from ./boost/archive/iterators/mb_from_wchar.hpp:31, from ./boost/archive/impl/xml_oarchive_impl.ipp:28, from libs\serialization\src\xml_oarchive.cpp:23: ./boost/archive/detail/utf8_codecvt_facet.hpp:20: warning: "BOOST_ARCHIVE_DECL" redefined 20 | #define BOOST_ARCHIVE_DECL | In file included from ./boost/archive/detail/auto_link_archive.hpp:26, from ./boost/archive/xml_oarchive.hpp:29, from libs\serialization\src\xml_oarchive.cpp:17: ./boost/archive/detail/decl.hpp:28: note: this is the location of the previous definition 28 | #define BOOST_ARCHIVE_DECL BOOST_SYMBOL_EXPORT | gcc.compile.c++ bin.v2\libs\serialization\build\gcc-mngw6\rls\cxstd-11-iso\thrd-mlt\vsblt-hdn\xml_archive_exception.o gcc.compile.c++ bin.v2\libs\serialization\build\gcc-mngw6\rls\cxs