> it absolutely does not care for kernel ABI stability

That may be true on the mach system call side, but the UNIX system calls don't appear to change. (Virgil actually does call the kernel directly).

> That may be true on the mach system call side, but the UNIX system calls don't appear to change.

They very much do, without warning, as the Go project discovered (after having been warned multiple times) during the Sierra betas: https://github.com/golang/go/issues/16272 https://github.com/golang/go/issues/16606

That doesn't mean Apple goes outs of its way to break syscalls (unlike microsoft), but there is no support for direct syscalls. That is why, again, you can't statically link libSystem.

> (Virgil actually does call the kernel directly).

That's completely unsupported ¯\_(ツ)_/¯

Another example: https://github.com/jart/cosmopolitan/issues/426

Nice I had not seen these.