Index: head/graphics/fig2sxd/Makefile
===================================================================
--- head/graphics/fig2sxd/Makefile	(revision 462484)
+++ head/graphics/fig2sxd/Makefile	(revision 462485)
@@ -1,28 +1,35 @@
 # Created by: Emanuel Haupt <ehaupt@critical.ch>
 # $FreeBSD$
 
 PORTNAME=	fig2sxd
 PORTVERSION=	0.22.1
 CATEGORIES=	graphics converters
 MASTER_SITES=	LOCAL/ehaupt SF
 DISTNAME=	${PORTNAME}_${PORTVERSION}.orig
 
 MAINTAINER=	ehaupt@FreeBSD.org
 COMMENT=	Convert .xfig files to the OpenOffice draw format
 
 USES=		gmake
 
 WRKSRC=		${WRKDIR}/${PORTNAME}-${PORTVERSION}
 
 PLIST_FILES=	bin/fig2sxd man/man1/fig2sxd.1.gz
 
+.include <bsd.port.pre.mk>
+
+# does not compile with clang 6.0.0
+.if ${OPSYS} == FreeBSD && ${OSVERSION} >= 1200056
+USE_GCC=	yes
+.endif
+
 post-patch:
 	@${REINPLACE_CMD} -e \
 		'/^CXX/d; s|^\(all:\).*|\1 $$(TARGET1) fig2sxd.1|' \
 			${WRKSRC}/${MAKEFILE}
 
 do-install:
 	${INSTALL_PROGRAM} ${WRKSRC}/${PORTNAME} ${STAGEDIR}${PREFIX}/bin
 	${INSTALL_MAN} ${WRKSRC}/${PORTNAME}.1 ${STAGEDIR}${MANPREFIX}/man/man1
 
-.include <bsd.port.mk>
+.include <bsd.port.post.mk>