With LynxOS 2.5.0-FCS version: 012797-G, you'll need to apply this patch:

    ftp://ftp.lynx.com/pub/patches/v2.5-patches/v2.5-on-x86/000134-00.tar.Z

And, you'll need to apply the following four patches:

1. `Patch /usr/include/netinet/in.h`:

       --- in.h.ORIGINAL	Sat Feb  8 09:58:28 1997
       +++ in.h	Wed Nov 26 15:41:04 1997
       @@ -278,8 +278,7 @@
        	compiler, the macros are not defined:  Functions must be used.
        */
        static __inline__ unsigned short
       -htons(arg)
       -unsigned short arg;
       +htons(unsigned short arg)
        {
        	unsigned short retval;

       @@ -292,8 +291,7 @@
        }

        static __inline__ unsigned long
       -htonl(arg)
       -unsigned long arg;
       +htonl(unsigned long arg)
        {
       	unsigned long retval;

2. `Patch /usr/include/name.h`:

       --- name.h.ORIGINAL	Sat Feb  8 11:57:36 1997
       +++ name.h	Wed Dec 24 11:00:57 1997
       @@ -112,7 +112,11 @@
        static __inline__ int _name_fchmod(int nsid, mode_t mode)
        { return _name_server(_NS_FCHMOD, nsid, mode); }

       +#if defined __cplusplus
       +static __inline__ int _name_fchown(int /* nsid */, uid_t owner, gid_t group)
       +#else
        static __inline__ int _name_fchown(int nsid, uid_t owner, gid_t group)
       +#endif /* __cplusplus */
        { return _name_server(_NS_FCHOWN, owner, group); }

        static __inline__ int _name_close(int nsid)

3. `Patch /usr/include/scsi.h`:

       --- scsi.h.ORIGINAL	Sat Feb  8 09:57:43 1997
       +++ scsi.h	Mon Dec  1 09:13:13 1997
       @@ -166,7 +166,7 @@
        ------------------------------------------------------------------------------
        */
        #define GET_DATA_BUFFER_STATUS          0x34	/* O     14.2.1 */
       -#define GET WINDOW                      0x25	/* O     14.2.2 */
       +#define GET_WINDOW                      0x25	/* O     14.2.2 */
        #define OBJECT_POSITION                 0x31	/* O     14.2.3 */
        #define SCAN                            0x1B	/* O     14.2.5 */
        #define SET_WINDOW                      0x24	/* M     14.2.6 */

4. `Patch /usr/include/netdb.h`:

       --- netdb.h.ORIGINAL	Sat Feb  8 09:57:36 1997
       +++ netdb.h	Mon Dec  1 10:57:15 1997
       @@ -95,6 +95,8 @@
        extern struct protoent	*getprotobyname	_AP((char *));
        extern struct protoent  *getprotobynumber _AP((int));
        extern struct protoent  *getprotoent	_AP((void));
       +int sethostent _AP((int));
       +int endhostent _AP((void));

        /*
         * Error return codes from gethostbyname() and gethostbyaddr()