--- src/libs/libpng-1.2.54/config.guess.orig	2020-07-10 02:58:17.000000000 +1000
+++ src/libs/libpng-1.2.54/config.guess	2020-08-21 15:09:26.961259000 +1000
@@ -156,6 +156,15 @@
 # Note: order is significant - the case branches are not exclusive.
 
 case "${UNAME_MACHINE}:${UNAME_SYSTEM}:${UNAME_RELEASE}:${UNAME_VERSION}" in
+    *:BSDSUniX:*:*)
+	UNAME_PROCESSOR=`/usr/bin/uname -p`
+	case ${UNAME_PROCESSOR} in
+	    amd64)
+		echo x86_64-unknown-bsdsunix`echo ${UNAME_RELEASE}|sed -e 's/[-(].*//'` ;;
+	    *)
+		echo ${UNAME_PROCESSOR}-unknown-bsdsunix`echo ${UNAME_RELEASE}|sed -e 's/[-(].*//'` ;;
+	esac
+	exit ;;
     *:NetBSD:*:*)
 	# NetBSD (nbsd) targets should (where applicable) match one or
 	# more of the tuples: *-*-netbsdelf*, *-*-netbsdaout*,