. It appears as though diablo is problematic on 5.x still, so default to

bootstrapping with the Linux JDK if there isn't a previously compiled
  native one.

java/jdk13/Makefile

@@ -111,6 +111,10 @@ LD_LIBRARY_PATH_FILES=	../src/solaris/javavm/runtime/javai_md.c \
 
 .include <bsd.port.pre.mk>
 
+.if ${OSVERSION} >= 500000 && !exists(${PREFIX}/jdk${JDK_VERSION}/bin/javac)
+WITH_LINUX_BOOTSTRAP=yes
+.endif
+
 .if !defined(JDK13DIR)
 .if defined(WITH_LINUX_BOOTSTRAP)
 JDK13DIR=	${LOCALBASE}/linux-blackdown-jdk${JDK_VERSION}