Why is my unit test failing via Hudson/Phing, but succeeding via Phing on the command line?

General Info:

PHP 5.3.3

PHPUnit 3.4

Zend Framework 1.10.8

Phing build target

 <target name="test">
  <echo msg="PHPUnit..." />
  <phpunit codecoverage="false" haltonfailure="true" haltonerror="true" printsummary="true" bootstrap="${testdir}/application/bootstrap.php">
   <batchtest>
    <fileset dir="${testdir}">
     <include name="**/*Test.php" />
     <exclude name="./application/ControllerTestCase.php" />
     <exclude name="./application/bootstrap.php" />
    </fileset>
   </batchtest>
   <formatter type="xml" todir="${builddir}" outfile="phpunit-results.xml" />
  </phpunit>
  <phpunitreport infile="${builddir}/phpunit-results.xml" 
     styledir="${phpunit.styles.dir}"
     format="frames" 
     todir="${builddir}" />
 </target>

This works...

phing -f build.xml test

Hudson/Phing

My Phing target listed in Hudson, which uses the same build.xml file, does not work. I get the same type of error (strpos(): Empty delimiter) for every unit test, which occurs whenever $this->dispatch(..url..) is executed.

Occurs within the console output upon execution of the unit test target in Hudson

'strpos(): Empty delimiter' in /opt/phing/classes/phing/tasks/ext/phpunit/PHPUnitTask.php:279

Within the PHPUnit results XML file

strpos(): Empty delimiter

/opt/zend/library/Zend/Controller/Request/Http.php:504
/opt/zend/library/Zend/Controller/Request/Http.php:551
/opt/zend/library/Zend/Controller/Request/Http.php:615
/opt/zend/library/Zend/Test/PHPUnit/ControllerTestCase.php:187
/var/lib/hudson/.hudson/jobs/IPS/workspace/trunk/tests/application/IndexControllerTest.php:6
/opt/phing/bin/phing.php:37

Can anyone shed some light on this?

Technically speaking, I solved this problem, but by deciding not to run PHPUnit via a Hudson Phing target. Instead, I decided to run a shell command in Hudson, which at the moment works fine for our needs. If anyone has any other ideas, I'm all ears. Thanks!