diff -urN /usr/ports/devel/boehm-gc.old/Makefile /usr/ports/devel/boehm-gc/Makefile
--- /usr/ports/devel/boehm-gc.old/Makefile	2014-12-08 19:27:07.000000000 +0100
+++ /usr/ports/devel/boehm-gc/Makefile	2014-12-15 15:40:04.000000000 +0100
@@ -3,7 +3,7 @@
 
 PORTNAME=	gc
 PORTVERSION=	7.4.2
-PORTREVISION=	2
+PORTREVISION=	3
 CATEGORIES=	devel
 MASTER_SITES=	http://www.hboehm.info/gc/gc_source/
 PKGNAMEPREFIX=	boehm-
@@ -56,6 +56,10 @@
 
 NOT_FOR_ARCHS=	ia64
 
+# no rule to get .lo from .S in subdirectory
+pre-build:
+	${LN} -sf ${WRKSRC}/src/sparc_mach_dep.S ${WRKSRC}
+
 .include <bsd.port.options.mk>
 
 .if ${PORT_OPTIONS:MDEBUG}