Unreferenced failing target in main build

In main build.xml, at row 1347, there's a (failing) unreferenced target
–
<target name="build-test-jars" description="Build jar files used in tests." depends="buildsource" >

    <ant dir="${derby.testing.src.dir}/${derby.testing.functest.dir}/tests/lang" target="build-test-jars" />

</target>
–
when executed the dir attribute expands to
     java\org.apache.derby.tests\org\apache\derbyTesting\functionTests\tests\lang\build.xml
that don't exists.
BUT the destination target 'build-test-jars' EXISTS in secondary build file
     java\org.apache.derby.tests\build.xml
and launching it's 'build-test-jars' target creates a db with
     java\org.apache.derby.tests\org\apache\derbyTesting\functionTests\tests\lang\nast_init.sql
and store it overwriting the already existent
    java\org.apache.derby.tests\org\apache\derbyTesting\functionTests\tests\lang\nast1.jar
that, in turn, is referenced by the test class
    java\org.apache.derby.tests\org\apache\derbyTesting\functionTests\tests\lang\NativeAuthenticationServiceTest.java

So, maybe, it's only an unreferenced target, activating it destroys nast1.jar and could be safely removed along
     build-test-jars target
in
    java\org.apache.derby.tests\build.xml

I've attached a svn.diff patch to delete this 2 targets.

Best regards, Davide Grandi

PS : BTW, discovered while extending the ant-antcall expansion from 'buildsource' to 'all' targets.
Nearly finished, it should have minimal impact on current osgi works.