Index: head/devel/py-python-dtrace/Makefile
===================================================================
--- head/devel/py-python-dtrace/Makefile	(revision 518293)
+++ head/devel/py-python-dtrace/Makefile	(revision 518294)
@@ -1,18 +1,22 @@
 # $FreeBSD$
 
 PORTNAME=	python-dtrace
 PORTVERSION=	0.0.9
 CATEGORIES=	devel python
 MASTER_SITES=	CHEESESHOP
 PKGNAMEPREFIX=	${PYTHON_PKGNAMEPREFIX}
 
 MAINTAINER=	gcj21@cl.cam.ac.uk
 COMMENT=	DTrace consumer for Python based on libdtrace
 
 LICENSE=	MIT
 LICENSE_FILE=	${WRKSRC}/LICENSE
 
 USES=		python zip
 USE_PYTHON=	autoplist distutils cython cython_run
 
+.if !exists(${SRC_BASE}/sys/cddl/contrib/opensolaris/uts/common/dtrace.h)
+IGNORE=		you must have "device dtrace" included in your kernel to build this package
+.endif
+
 .include <bsd.port.mk>