https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93082
--- Comment #10 from Iain Sandoe <iains at gcc dot gnu.org> --- I also have a few "clang compatibility workarounds" for GCC (including one for this specific case) - but they need putting behind some "-fclang-compatibility" flag or so. Hopefully, will work on integrating them in GCC-13. In some cases that is going to work better than a fix includes. FWIW this is not actually a bug in GCC, the bug is in the headers as Andrew points out (the value is valid in C++ but not for C): " Funny how clang thinks this was an GNU extension when it is not one." I do not currently have a plan to try and build a second fix includes tree for Frameworks, but happy to review patches if someone else does :)