https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89864
--- Comment #90 from Iain Sandoe <iains at gcc dot gnu.org> --- (In reply to Zaak from comment #89) > Anyone have a patch for 4.9? A user wants one, but I can't build 4.9 from > source on Mojave. 4.9is long-closed [as are 5, 6] , is there some reason the user can't move forward? (I was not considering back-porting anything to earlier than 5.5/6.5 and that would be out of tree "vendor branches" in git since SVN is closed as noted) In the short-term you could try back porting the 8.3 patch to 4.9 fixincludes/fixincl.def and then regenerating the fixincl.x. (unless there are other problems for 4.9 on 10.14)