Add this to your Wicket application class to limit Wicket dev mode warning to one per JVM instead of per test. Reduces clutter in build log.

gistfile1.java

private static boolean warnedAboutDevMode = false;

@Override
protected void outputDevelopmentModeWarning() {
    if (warnedAboutDevMode) {
        return;
    }
    super.outputDevelopmentModeWarning();
    warnedAboutDevMode = true;
}