diff -Naur tcl8.6.11/unix/tclUnixSock.c tcl8.6.11.serenity/unix/tclUnixSock.c
--- unix/tclUnixSock.c	2020-09-21 17:15:49.000000000 +0200
+++ unix.serenity/tclUnixSock.c	2021-04-25 09:39:28.224340150 +0200
@@ -706,6 +706,7 @@
 IPv6AddressNeedsNumericRendering(
     struct in6_addr addr)
 {
+#ifndef __serenity__
     if (IN6_ARE_ADDR_EQUAL(&addr, &in6addr_any)) {
         return 1;
     }
@@ -716,11 +717,15 @@
      */
 
     if (!IN6_IS_ADDR_V4MAPPED(&addr)) {
+#else
         return 0;
+#endif
+#ifndef __serenity__
     }
 
     return (addr.s6_addr[12] == 0 && addr.s6_addr[13] == 0
             && addr.s6_addr[14] == 0 && addr.s6_addr[15] == 0);
+#endif
 }
 #if defined (__clang__) || ((__GNUC__)  && ((__GNUC__ > 4) || ((__GNUC__ == 4) && (__GNUC_MINOR__ > 5))))
 #pragma GCC diagnostic pop