From c8ffee3460a1b507bbc7f5f83e4e09e4a769db76 Mon Sep 17 00:00:00 2001
From: Brian White <mscdex@mscdex.net>
Date: Fri, 31 May 2013 18:37:45 -0400
Subject: [PATCH] freebsd: don't enable dtrace if it's not available

---
 config-unix.mk | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/config-unix.mk b/config-unix.mk
index 347d9d77..a7592591 100644
--- a/config-unix.mk
+++ b/config-unix.mk
@@ -106,7 +106,9 @@ OBJS += src/unix/linux-core.o \
 endif
 
 ifeq (freebsd,$(PLATFORM))
+ifeq ($(shell dtrace -l 1>&2 2>/dev/null; echo $$?),0)
 HAVE_DTRACE=1
+endif
 LDFLAGS+=-lkvm
 OBJS += src/unix/freebsd.o
 OBJS += src/unix/kqueue.o