Fix compile issue on MacOSX

```C
// #if !defined(__FreeBSD__) && !defined(__APPLE__)
#ifndef __FreeBSD__ 
  #ifdef __APPLE__
    #include <mach/error.h>
  #else
    #include <sys/error.h> 
  #endif
#endif
```

Not 100% sure if macosx needs error.h but it works.