Problem getting at the goodies (specifically, serverURL) in my Grails Config.groovy at runtime?

Question

Similar to question 198365, I'm trying to access serverURL in Config.groovy, during bootstrap. Using code from that question/answer, I'm getting a value of null. Is there something else I'm missing?

    import org.codehaus.groovy.grails.commons.ConfigurationHolder;

    def serverURL = ConfigurationHolder.config.grails.serverURL;
    println("==========  serverURL: " + serverURL);

Output:

========== serverURL: null