ant task throws NoClassDefFoundError - Tomcat 8.0.18

[Gernot]

Hi!

I'm using Tomcat 8.0.18.
I've following ant build.xml:

<import file="${tomcat.home}/bin/
catalina-tasks.xml"/>

   <target name="jspc">

    <jasper
             validateXml="false"
             uriroot="${webapp.path}"
             webXmlFragment="${webapp.path}/WEB-INF/generated_web.xml"
             outputDir="${webapp.path}/WEB-INF/src" />

  <validator path="${webapp.path}" />
...
  </target>

<jasper> task works great, but <validator> task throws
java.lang.NoClassDefFoundError: org/apache/catalina/Globals
I have not found any documentation for <validator> task for Tomcat 8. Is
there any additional configuration necessary (in contrast to Tomcat
5.5/6/7)?