On Oct 26, 2018, at 15:29, Riccardo Mottola wrote: > This gives me another clue: if it is ld64 is it building a universal binary? I am on a 32bit Mac. No, ld64 is just the name of Apple's linker. It works for 32-bit and 64-bit. Which one is used depends on your -arch or -m flags as usual.