org.eclipse.wtp.releng.webupdatesite/build-home/updateMirrorProject.xml

<?xml version="1.0" encoding="UTF-8"?>
<project name="update" default="update" basedir=".">
    <!-- original example received from Richard Gronback from cross-project list (thanks Richard!) -->
    <!-- see http://help.eclipse.org/help31/index.jsp?topic=/org.eclipse.platform.doc.isv/reference/misc/update_standalone.html -->

    <target name="init" unless="initialized">
        <ant antfile="init.xml" />
    </target>

    <target name="update" depends="init">
        <echo message="Updating ${featureId} ${version}" />
        <java jar="${eclipseLocation}/startup.jar"
              fork="true"
              failonerror="false">
            <jvmarg value="-DcontinueOnError=true" />
            <arg value="-clean" />
            <arg value="-nosplash" />
            <arg value="-application" />
            <arg value="org.eclipse.update.core.standaloneUpdate" />
            <arg value="-data" />
            <arg value="${basedir}/buildworkspace" />
            <arg value="-debug" />
            <arg value="-consolelog" />
            <arg value="-command" />
            <arg value="mirror" />
            <arg value="-featureId" />
            <arg value="${featureId}" />
            <arg value="-version" />
            <arg value="${version}" />
            <arg value="-from" />
            <arg value="${updateSite}" />
            <arg value="-to" />
            <arg value="${localUpdateSitePath}" />
            <arg value="-ignoreMissingPlugins" />
            <arg value="true" />

        </java>

    </target>
</project>