Force Phing to Fail on CakePHP tests

phing.cakephp.xml

 <target name="caketest-local" description="Run CakePHP unit tests with PHPUnit and print human readable output.">
        <exec dir="${basedir}" executable="${basedir}/app/Console/cake" output="${logdir}/caketest.log" returnProperty="test_result">
            <arg line="test" />
            <arg line="--stderr"/>
            <arg line="--configuration=${basedir}/phpunit-coverage-text.xml" />
            <arg line="app" />
            <arg line="AllTests" />
        </exec>
        <if>
            <not>
                <equals arg1="${test_result}" arg2="0"/>
            </not>
            <then>
                <fail msg="Build FAILED! Check caketest.log for details"/>
            </then>
        </if>
    </target>