https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87030
--- Comment #3 from Iain Sandoe <iains at gcc dot gnu.org> --- Just a few notes: 1. I'm not objecting to some kind of automation to switch off the 32b multiline where the *target* system is >= 10.14/Darwin18 (someone needs to write it, that's all). 2. Actually, you get the same failure on GNU-Linux if you try to configure defaults on (for example) an x86_64 system without 32bit libs installed (one has to add --disable-multilib there, or install 32b libs), so automation is not the default on Linux. 3. I don't see why GCC should be subject to the vendor's support policy. As far as I am concerned, with the right SDK / sysroot available, there's no reason why a compiler *hosted* on x86-64-Darwin18 shouldn't be able to build code for i686-darwin10 *target*.