title: How do I make an executable that readelf would say is UNIX - System V?
body: <p>I have been making programs for ages that are under 800K on Linux Fedora 19 using GCC 4.8.1.  The readelf utility has reported them as OS/ABI = "UNIX - System V" (byte 8 is zero).   </p>
  
  <p>Now suddenly the binaries are turning out over 1MB and readelf is saying they are "UNIX - GNU" (byte 8 is 3).  Not my doing!  Something is having an influence and I'm not sure what.  </p>
  
  <p>For instance, now, using nm, I find that the functions __nss_hosts_lookup2 and openat are being linked in, which weren't there before.  </p>
  
  <p>How do I make an executable again that readelf would say is UNIX - System V ?</p>