Don't forget the fe-connect.h include file

src/interfaces/libpq/fe-connect.h

+/*-------------------------------------------------------------------------
+ *
+ * fe-connect.h
+ *
+ *    Definitions related to setting up a connection to the backend
+ *
+ * Copyright (c) 1994, Regents of the University of California
+ *
+ * $Id: fe-connect.h,v 1.1 1997/03/16 19:06:04 scrappy Exp $
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef FE_CONNECT_H
+#define        FE_CONNECT_H
+
+/*----------------------------------------------------------------
+ * Common routines and definitions
+ *----------------------------------------------------------------
+ */
+
+extern int packetSend(Port *port, PacketBuf *buf, PacketLen len, bool nonBlocking);
+
+#endif /* FE_CONNECT_H */
+#ifndef FE_CONNECT_H
+#define FE_CONNECT_H
+
+int packetSend(Port *port, PacketBuf *buf, PacketLen len, bool nonBlocking);
+
+#endif