Jenkins-Phing-PHPUnit formatter not working

Replaced your selenium target with a little customized phpunit target which works for me on Linux (CentOS/Debian) for PHP 5.5, 5.6 and 7.0.

<?xml version="1.0" encoding="UTF-8" ?><project name="Webshop" default="phpunit">    <property name="myproject.lib.dir" value="${project.basedir}/vendor" />    <property name="selenium.logs.dir" value="${project.basedir}/build/logs" />    <property name="selenium.logs.file" value="junit-selenium.xml" />    <property name="selenium.tests.dir" value="${project.basedir}/tests" />    <target name="prepare" depends="clean">        <mkdir dir="${selenium.logs.dir}"/>    </target>    <target name="clean">        <delete dir="${selenium.logs.dir}"/>    </target>    <target name="selenium" description="Run all selenium tests of Webshop" depends="prepare">        <!-- Please change pharlocation. Vendor/bin/phpunit shouldn't be used with phing. -->        <phpunit bootstrap="${myproject.lib.dir}/autoload.php" pharlocation="${myproject.lib.dir}/bin/phpunit">            <formatter type="xml" todir="${selenium.logs.dir}" />            <batchtest>                <fileset dir="${selenium.tests.dir}"/>            </batchtest>        </phpunit>    </target>    <fileset id="phptests" dir="${selenium.tests.dir}"/>    <target name="phpunit" description="Run unit tests" depends="prepare">        <coverage-setup database="${selenium.logs.dir}/coverage.db">            <fileset refid="phptests"/>        </coverage-setup>        <phpunit haltonfailure="true" haltonerror="true" printsummary="true" bootstrap="${myproject.lib.dir}/autoload.php"                 codecoverage="true">            <formatter todir="${selenium.logs.dir}" type="clover" outfile="clover.xml" />            <formatter todir="${selenium.logs.dir}" type="xml" outfile="junit.xml" />            <batchtest>                <fileset refid="phptests"/>            </batchtest>        </phpunit>    </target></project>

Your build.xml for phing looks ok at first sight, but for some reason you seem to miss the usefile="true" argument in your formatter block.

<formatter type="xml" usefile="true" todir="${selenium.logs.dir}" outfile="${selenium.logs.file}"></formatter>

Try this out to see how it works for you.