Index: Makefile
===================================================================
--- Makefile	(revision 563552)
+++ Makefile	(working copy)
@@ -128,6 +128,11 @@
 PLIST_SUB+=	PANGOCAIRO="@comment "
 .endif
 
+.if defined(WITH_DEBUG)
+LDFLAGS+=	-lexecinfo
+.endif
+
+
 post-patch:
 .if ${CHOSEN_COMPILER_TYPE} == clang
 	${REINPLACE_CMD} -e '/altivec.h/d' ${WRKSRC}/gegl/opencl/cl_platform.h