[ploxiln]

The root of the issue is that, while you can write most of the code in C (but not all), it has to be different for different operating system kernels. It will use different syscall numbers, argument size and order and "extra options" will be different, some kernels will have a more general syscall with options that enable it to be used for a handful of similar standard libc wrapper functions ...

On macOS, you're really supposed to always dynamically link to the libSystem.dylib libc implementation, because the macOS kernel has subtle backwards-incompatible changes in the raw syscall interfaces on every macOS release (maybe even in point-release updates, I'm not sure). Go tried to have its own internal static libc replacement for macOS like it does for Linux, but just a year or two ago Go gave that up, and now dynamically links the macOS libc.