Union + Tar

[Jon Stevens]

I've got my class which extends Union typedef. Inside of it are a bunch of
FileList's which in turn have a bunch of FileResources.

    <sunion id="all.classpath" scope="all">
        <sfilelist dir="${lib.dir}">
            <sfile name="${activation.jar}" scope="compile" />
        </sfilelist>
    </sunion>

Now, I'd like to reference that Union within a <tarfileset>... something
like this:

        <tar destfile="${target.dir}/${project.name}.tgz" compression="gzip"
longfile="gnu">
            <tarfileset prefix="lib">
                <resources refid="all.classpath" />
            </tarfileset>
        </tar>

I'm getting this error (ant 1.8.1):

only single argument resource collections are supported as archives

Idea's? One workaround is to create the directory structure first by copying
files, but that is kind of lame. =)

        <copy todir="${target.dir}/dist/lib">
           <union refid="all.classpath" />
        </copy>

jon