dependencies picking up strange CFLAGS


I’m not sure if this happens on other platforms as well, but I am noticing that dependencies like GMP are picking up strange flags like “-march=k8 -mtune=k8” on macOS, even when MARCH is set to ‘native’ (it actually puts -march=native and then cancels it out by adding the other, wrong ones). Does anyone know where all of these flags are coming from?