Index: /issm/trunk-jpl/etc/environment.sh
===================================================================
--- /issm/trunk-jpl/etc/environment.sh	(revision 28143)
+++ /issm/trunk-jpl/etc/environment.sh	(revision 28144)
@@ -203,5 +203,7 @@
 
 	if [[ ${BUILD_TOOL_VER} -ge 15 ]]; then
-		export LDFLAGS="-Wl,-ld_classic"
+		export LDFLAGS="${LDFLAGS} -Wl,-ld_classic"
+	else
+		export LDFLAGS="${LDFLAGS}" # At least set LDFLAGS to null string if it is not already set (used in installation of ISSM and some external packages). Can remove this when issues with new Xcode linker have settled.
 	fi
 fi