anchor.diff:  -define(EIO, eio).
   -define(EISCONN, eisconn).
   -define(EISDIR, eisdir).
  +-define(EKEYEXPIRED, ekeyexpired).
   -define(ELOOP, eloop).
   -define(EMFILE, emfile).
   -define(EMLINK, emlink).
  
positive.code:     | ?ECANCELED | ?ECHILD | ?ECONNABORTED | ?ECONNREFUSED | ?ECONNRESET
      | ?EDEADLK | ?EDESTADDRREQ | ?EDOM | ?EEXIST | ?EFAULT | ?EFBIG
      | ?EHOSTUNREACH | ?EIDRM | ?EILSEQ | ?EINPROGRESS | ?EINTR | ?EINVAL | ?EIO
      | ?EISCONN | ?EISDIR | ?ELOOP | ?EMFILE | ?EMLINK | ?EMSGSIZE
      | ?ENAMETOOLONG | ?ENETDOWN | ?ENETRESET | ?ENETUNREACH | ?ENFILE | ?ENOBUFS
      | ?ENODATA | ?ENODEV | ?ENOENT | ?ENOEXEC | ?ENOLCK | ?ENOLINK | ?ENOMEM
      | ?ENOMSG | ?ENOPROTOOPT | ?ENOSPC | ?ENOSR | ?ENOSTR | ?ENOSYS | ?ENOTCONN
  
negative.code:     ?EALREADY, ?EBADF, ?EBADMSG, ?EBUSY, ?ECANCELED, ?ECHILD, ?ECONNABORTED,
      ?ECONNREFUSED, ?ECONNRESET, ?EDEADLK, ?EDESTADDRREQ, ?EDOM, ?EEXIST,
      ?EFAULT, ?EFBIG, ?EHOSTUNREACH, ?EIDRM, ?EILSEQ, ?EINPROGRESS, ?EINTR,
      ?EINVAL, ?EIO, ?EISCONN, ?EISDIR, ?EKEYEXPIRED, ?ELOOP, ?EMFILE, ?EMLINK, ?EMSGSIZE,
      ?ENAMETOOLONG, ?ENETDOWN, ?ENETRESET, ?ENETUNREACH, ?ENFILE, ?ENOBUFS,
      ?ENODATA, ?ENODEV, ?ENOENT, ?ENOEXEC, ?ENOLCK, ?ENOLINK, ?ENOMEM, ?ENOMSG,
      ?ENOPROTOOPT, ?ENOSPC, ?ENOSR, ?ENOSTR, ?ENOSYS, ?ENOTCONN, ?ENOTDIR,
  