For PHPUnit tag is supported in phing's build.xml. What to do if the automated tests use phpRack? i.e. extend phpRack_Test class
The phpRack docs say that phpRack can be integrated with phing
like this:
<target name="phpRack" description="Validate all integration tests">
<http-request
url="http://example.com/phprack.php?suite"
authUser="john"
authPassword="jf7mF4"
responseRegex="/PHPRACK SUITE: OK/"
verbose="true"
observerEvents="connect, receivedBody, disconnect"
/>
</target>
By making this phing task fail when the result doesn't contain "OK" your build will also fail.
I have no clue how you can store the resulting page with phing though.