The secondary launcher is not created on Mac OS when it's specified under build.xml (Java API is also affected).

build.xml:

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<project xmlns:fx="javafx:com.sun.javafx.tools.ant" default="fx-deploy">
    <taskdef classpath="/Users/gtee/work/dmitry.ginzburg/appBundlerTests-8u40/lib/ant-javafx.jar" resource="com/sun/javafx/tools/ant/antlib.xml" uri="javafx:com.sun.javafx.tools.ant"/>
    <target name="fx-deploy">
        <fx:deploy nativeBundles="image" outdir="/var/folders/_w/k9hb3psj3112n5pyn8q2qbj00000gp/T/testBundlerWorkDir3434424700255345356" outfile="test" verbose="true">
            <fx:resources>
                <fx:fileset dir="/var/folders/_w/k9hb3psj3112n5pyn8q2qbj00000gp/T/testBundlerWorkDir3434424700255345356/jars" includes="Util.jar,testFxAppWithUtil.jar"/>
            </fx:resources>
            <fx:platform/>
            <fx:preferences/>
            <fx:application name="SQE-TEST-APP"/>
            <fx:info/>
            <fx:secondaryLauncher>
                <fx:jvmuserarg name="-Xmx" value="1g"/>
                <fx:jvmuserarg name="-Xms" value="512m"/>
                <fx:bundleArgument arg="applicationClass" value="testapp.App2"/>
                <fx:property name="sqe.aba.caba" value="dabacaba"/>
                <fx:bundleArgument arg="name" value="SQE-ninja"/>
                <fx:jvmarg value="-Dsqe.foo.bar=baz"/>
                <fx:jvmarg value="-Dsqe.qux.corge=grault"/>
            </fx:secondaryLauncher>
            <fx:bundleArgument arg="mainJar" value="testFxAppWithUtil.jar"/>
            <fx:bundleArgument arg="classpath" value="testFxAppWithUtil.jar:Util.jar"/>
        </fx:deploy>
    </target>
</project>

After ant execution content of .../SQE-TEST-APP.app/Contents/MacOS: [SQE-TEST-APP (main application), libpackager.dylib]