https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100017
--- Comment #10 from cqwrteur <unlvsur at live dot com> --- (In reply to Jonathan Wakely from comment #8) > I can only fix the case where the target <fenv.h> (in the build tree) is > found first and then its #include_next finds the host <fenv.h> (installed on > the host). > > But that seems to be the case that's breaking the canadian cross build. The same issue happens with x86_64-linux-gnu build, x86_64-w64-mingw32 host, x86_64-ubuntu-linux-gnu target /home/cqwrteur/myhome/glibc231/mingw_toolchain/mingw-host-linux/gcc/x86_64-ubuntu-linux-gnu/libstdc++-v3/include/cfenv:77:11: error: 'feupdateenv' has not been declared in '::' 77 | using ::feupdateenv; Looks like it has something to do with fenv.h
