Enable SO_NOSIGPIPE for sockets on OS X.

lib/pure/net.nim

@@ -205,6 +205,10 @@ proc newSocket*(fd: SocketHandle, domain: Domain = AF_INET,
   if buffered:
     result.currPos = 0
 
+  # Set SO_NOSIGPIPE on OS X.
+  when defined(macosx):
+    setSockOptInt(fd, SOL_SOCKET, SO_NOSIGPIPE, 1)
+
 proc newSocket*(domain, sockType, protocol: cint, buffered = true): Socket =
   ## Creates a new socket.
   ##