Gentoo's Bugzilla –
Attachment 448642 Details for
Bug 595742sys-libs/libcxxrt-0.0_p20160922 - src_test(): test_exception.cc: In destructor ‘uncaught_exceptions_checker::~uncaught_exceptions_checker()’: test_exception.cc:221:18: error: ‘uncaught_exceptions’ is not a member of ‘std’