Hmm no idea. I only build 1 OS on my Mac: https://github.com/mit-pdos/xv6-public https://github.com/mit-pdos/xv6-public. It obviously won't compile with Apple'

Hmm no idea. I only build 1 OS on my Mac: https://github.com/mit-pdos/xv6-public https://github.com/mit-pdos/xv6-public. It obviously won't compile with Apple's gcc (which actually is a clang wrapper), so have to install another compiler (i386-elf-gcc). But on my Debian box, it works with the standard gcc.