Jenkins Ant Task 1.8.3 default variable is not working

I'm trying to implement Jenkins with RTC, but I run into an issue when I trying to use invoke Ant in the build step. 

           Ant task attribute "buildResultUUID" contains illegal value "${env.RTCBuildResultUUID}".

I thought env.RTCBuildResultUUID is a variable that is build-in within Ant, so I don't need to set the variable. 

This is our setup in build.xml file:

            <property environment="env" />

             <property name="buildResultID" value="${env.BuildResultUUID}" />