<property name="classes.dir" value="${build.dir}/classes"/>

    <!-- tag::build-required[] -->
    <target name="buildRequiredProjects">
        <ant dir="${root.dir}/util" target="build"/>  <!--1-->
    </target>
    <!-- end::build-required[] -->

    <target name="compile" depends="buildRequiredProjects">
        <mkdir dir="${classes.dir}"/>

    <property name="classes.dir" value="${build.dir}/classes"/>

    <!-- tag::build-required[] -->
    <target name="buildRequiredProjects">
        <ant dir="${root.dir}/util" target="build"/>
    </target>
    <!-- end::build-required[] -->

    <target name="compile" depends="buildRequiredProjects">
        <mkdir dir="${classes.dir}"/>

Just be careful to remove or override any dependencies on tasks that delegate to other subprojects, like the `buildRequiredProjects` task.
 5. Identify the projects that have no dependencies on other projects and migrate them to idiomatic Gradle builds scripts.
+
Follow the advice in the rest of this guide to migrate individual project builds.