console operations not thread safe

[sheehan]

org.grails.web.converters.exceptions.ConverterException: java.lang.NullPointerException: Cannot get property 'args' on null object
        at org.grails.web.converters.marshaller.ClosureObjectMarshaller.marshalObject(ClosureObjectMarshaller.java:65)
        at grails.converters.JSON.value(JSON.java:184)
        at grails.converters.JSON.render(JSON.java:119)
        at grails.converters.JSON.render(JSON.java:132)
        at grails.artefact.controller.support.ResponseRenderer$Trait$Helper.render(ResponseRenderer.groovy:190)
        at grails.artefact.controller.support.ResponseRenderer$Trait$Helper$render$3.call(Unknown Source)
        at org.grails.plugins.console.ConsoleController.render(ConsoleController.groovy)