ant octane target fails with "Unable to load a script engine manager (org.apache.bsf.BSFManager or javax.script.ScriptEngineManager)"

$ ant -Doctane.iterations=5 octane


BUILD FAILED
D:\src\jdk9-dev\nashorn\make\build-benchmark.xml:281: The following error occurred while executing this line:
D:\src\jdk9-dev\nashorn\make\build-benchmark.xml:227: Unable to load a script engine manager (org.apache.bsf.BSFManager or javax.script.ScriptEngineManager)

With "ant debug" turned on, I got the following stack trace:

BUILD FAILED
D:\src\jdk9-dev\nashorn\make\build-benchmark.xml:281: The following error occurred while executing this line:
D:\src\jdk9-dev\nashorn\make\build-benchmark.xml:227: Unable to load a script engine manager (org.apache.bsf.BSFManager or javax.script.ScriptEngineManager)
        at org.apache.tools.ant.util.ScriptRunnerCreator.createRunner(ScriptRunnerCreator.java:95)
        at org.apache.tools.ant.util.ScriptRunnerHelper.getRunner(ScriptRunnerHelper.java:193)
        at org.apache.tools.ant.util.ScriptRunnerHelper.getScriptRunner(ScriptRunnerHelper.java:55)
        at org.apache.tools.ant.taskdefs.optional.Script.execute(Script.java:53)
        at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:293)
        at sun.reflect.GeneratedMethodAccessor4.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(java.base@9-internal/DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(java.base@9-internal/Method.java:531)
        at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106)
        at org.apache.tools.ant.Task.perform(Task.java:348)
        at org.apache.tools.ant.Target.execute(Target.java:435)
        at org.apache.tools.ant.Target.performTasks(Target.java:456)
        at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1405)
        at org.apache.tools.ant.helper.SingleCheckExecutor.executeTargets(SingleCheckExecutor.java:38)
        at org.apache.tools.ant.Project.executeTargets(Project.java:1260)
        at org.apache.tools.ant.taskdefs.Ant.execute(Ant.java:441)
        at org.apache.tools.ant.taskdefs.CallTarget.execute(CallTarget.java:105)
        at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:293)
        at sun.reflect.GeneratedMethodAccessor4.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(java.base@9-internal/DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(java.base@9-internal/Method.java:531)
        at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106)
        at org.apache.tools.ant.Task.perform(Task.java:348)
        at org.apache.tools.ant.Target.execute(Target.java:435)
        at org.apache.tools.ant.Target.performTasks(Target.java:456)
        at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1405)
        at org.apache.tools.ant.Project.executeTarget(Project.java:1376)
        at org.apache.tools.ant.helper.DefaultExecutor.executeTargets(DefaultExecutor.java:41)
        at org.apache.tools.ant.Project.executeTargets(Project.java:1260)
        at org.apache.tools.ant.Main.runBuild(Main.java:853)
        at org.apache.tools.ant.Main.startAnt(Main.java:235)
        at org.apache.tools.ant.launch.Launcher.run(Launcher.java:285)
        at org.apache.tools.ant.launch.Launcher.main(Launcher.java:112)

Total time: 8 seconds

Line 222227 in build-benchmark.xml is

    <script language="javascript"><![CDATA[

So, ant's use of javascript engine is failing.