Just to give you an idea of how much software GCC 14's default of -Werror=implicit-function-declaration breaks, here are two pkgsrc bulk build results:
GCC 13.3.0: 24835/28450
GCC 14.3.0: 2589/28450
reports.pkgci.org/SmartOS/upst…
reports.pkgci.org/SmartOS/upst…
I also had to fix up a bunch of things before the build would even start.
This could take a while. And then the fun starts all over again with GCC 15's changes...