JUnit 5 avec Ant junitlauncher : NoClassDefFoundError : org/junit/platform/launcher/core/LauncherFactory

Question

Je voudrais exécuter des tests junit5 en combinaison avec ant, plus précisément junitlauncher

Voici la structure de mon projet :

et voici mon fichier de construction :

<?xml version="1.0" encoding="UTF-8"?>
<project default="test" name="test">
    <property name="src.dir" value="${basedir}/src" />
    <property name="output.dir" value="${basedir}/build" />

    <!-- PATH DEFINITIONS -->
    <path id="junit5.classpath">
        <fileset dir="${basedir}/lib/" />
    </path>
    <path id="test.classpath">
        <path refid="junit5.classpath" />
        <fileset dir="${output.dir}">
            <include name="**/*.class" />
        </fileset>
    </path>

    <target name="clean">
        <delete dir="${output.dir}" />
    </target>

    <target name="compile" depends="clean">
        <mkdir dir="${output.dir}" />
        <mkdir dir="${output.dir}/report" />
        <javac srcdir="${src.dir}" destdir="${output.dir}" includeantruntime="false">
            <!-- test libs -->
            <classpath>
                <path refid="junit5.classpath" />
            </classpath>
        </javac>
    </target>

    <target name="test" depends="compile">
        <pathconvert property="classpathProp" refid="test.classpath"/>
        <echo>Classpath is ${classpathProp}</echo>
        <echo>Running junit tests...</echo>
        <junitlauncher>
            <classpath refid="test.classpath" />
            <test name="test.SomeClassTest" />
        </junitlauncher>
    </target>
</project>

Quand j'essaie d'exécuter la tâche de test, je peux voir le classpath :

Classpath is 
/Users/some-username/Documents/workspace/test/lib/junit-jupiter-api-5.3.0-SNAPSHOT.jar:
/Users/some-username/Documents/workspace/test/lib/junit-jupiter-engine-5.3.0-SNAPSHOT.jar:
/Users/some-username/Documents/workspace/test/lib/junit-jupiter-migrationsupport-5.3.0-SNAPSHOT.jar:
/Users/some-username/Documents/workspace/test/lib/junit-jupiter-params-5.3.0-SNAPSHOT.jar:
/Users/some-username/Documents/workspace/test/lib/junit-platform-commons-1.3.0-SNAPSHOT.jar:
/Users/some-username/Documents/workspace/test/lib/junit-platform-engine-1.3.0-SNAPSHOT.jar:
/Users/some-username/Documents/workspace/test/lib/junit-platform-launcher-1.3.0-SNAPSHOT.jar:
/Users/some-username/Documents/workspace/test/lib/junit-platform-runner-1.3.0-SNAPSHOT.jar:
/Users/some-username/Documents/workspace/test/lib/junit-platform-suite-api-1.3.0-SNAPSHOT.jar:
/Users/some-username/Documents/workspace/test/lib/junit-vintage-engine-5.3.0-SNAPSHOT.jar:
/Users/some-username/Documents/workspace/test/lib/junit.jar:
/Users/some-username/Documents/workspace/test/lib/org.apiguardian_1.0.0.v20180327-1502.jar:
/Users/some-username/Documents/workspace/test/lib/org.hamcrest.core_1.3.0.v20180420-1519.jar:
/Users/some-username/Documents/workspace/test/lib/org.opentest4j_1.0.0.v20180327-1502.jar:
/Users/some-username/Documents/workspace/test/build/test/SomeClass.class:
/Users/some-username/Documents/workspace/test/build/test/SomeClassTest.class:
/Users/some-username/Documents/workspace/test/build/test/TestSuite.class

suivi par :

ÉCHEC DE LA CONSTRUCTION /Users/some-username/Documents/workspace/test/build.xml:36 : java.lang.NoClassDefFoundError : org/junit/platform/launcher/core/LauncherFactory

vous pouvez trouver l'archive du projet eclipse ici : https://drive.google.com/file/d/161rYTopmqM3JMqv8kvM6VjJbG1sm-3k2/view?usp=sharing

Comment puis-je le faire fonctionner ? Qu'est-ce que j'ai manqué ?