295668 allow xulrunner location to be specified for unit tests
diff --git a/releng.wtpbuilder/components/wtp-patches3/dependency.xml b/releng.wtpbuilder/components/wtp-patches3/dependency.xml
index 36db1b5..f746619 100644
--- a/releng.wtpbuilder/components/wtp-patches3/dependency.xml
+++ b/releng.wtpbuilder/components/wtp-patches3/dependency.xml
@@ -13,6 +13,9 @@
     <target
         name="get">
 
+	 <fail message="depenendency.properties must be defined" unless="dependency.properties" />
+    	<available file="${dependency.properties}" property="dependenciesExists" />
+    	<fail message="The expected depenendency.properties, ${dependency.properties}, does not exist." unless="dependenciesExists" />
         <!--
             read in this properties, just so we can make sure our
             requested pre-reqs are defined