Index: head/www/firefox/Makefile.options
===================================================================
--- head/www/firefox/Makefile.options	(revision 410940)
+++ head/www/firefox/Makefile.options	(revision 410941)
@@ -1,21 +1,30 @@
 # -*- makefile-bsdmake -*-
 
 OPTIONS_DEFINE+= 	BUNDLED_CAIRO CANBERRA DBUS DEBUG DTRACE FFMPEG GCONF GIO \
 			GNOMEUI GSTREAMER INTEGER_SAMPLES LIBPROXY LOGGING \
 			OPTIMIZED_CFLAGS PGO PROFILE TEST
 
 OPTIONS_DEFAULT+=	DBUS DTRACE FFMPEG GIO GSTREAMER LOGGING OPTIMIZED_CFLAGS \
 			${OPTIONS_MULTI_AUDIO} \
 			${MACHINE_CPU:tu:MSOFTFP:S/SOFTFP/INTEGER_SAMPLES/}
 
 OPTIONS_MULTI+=		AUDIO
 OPTIONS_MULTI_AUDIO=	ALSA PULSEAUDIO
 
+# dragonfly, sparc64, riscv
+.if !exists(/usr/sbin/dtrace)
+OPTIONS_EXCLUDE+=	DTRACE
+.endif
+
+# dtrace(1) crashes during build
+OPTIONS_EXCLUDE_FreeBSD_9_i386+=	DTRACE
+OPTIONS_EXCLUDE+=	${OPTIONS_EXCLUDE_${OPSYS}_${OSREL:R}_${ARCH}}
+
 BUNDLED_CAIRO_DESC?=	Use bundled fork of cairo-1.9.5
 CANBERRA_DESC?=		Sound theme alerts
 ENIGMAIL_DESC?=		Enigmail extension
 GNOMEUI_DESC?=		libgnomeui support module
 INTEGER_SAMPLES_DESC?=	Integer audio sample format
 LIBPROXY_DESC?=		Proxy support via libproxy
 LIGHTNING_DESC?=	Calendar extension
 LOGGING_DESC?=		Additional log messages