add wtpcap build
diff --git a/releng.wtpbuilder/scripts/build/runbuild.xml b/releng.wtpbuilder/scripts/build/runbuild.xml
index 613629a..d0b9393 100644
--- a/releng.wtpbuilder/scripts/build/runbuild.xml
+++ b/releng.wtpbuilder/scripts/build/runbuild.xml
@@ -347,8 +347,10 @@
                 arg2="N" />
         </condition>
        
+    	<!-- exit if the component directory doesn't exist (for example, may not always be an "sdk" 
+    	component, but we often generate calls to it) -->
     	<condition property="doBuild" >
-    	 <available resource="${wtp.builder.home}/components/${component}" type="dir" />
+    	 <available file="${wtp.builder.home}/components/${component}" type="dir" />
     	</condition>
     	
     </target>