Phing can't see PHPUnit

Question

I\'m trying to setup a new Continuous Integration server that utilizes Phing and PHPUnit for automatically running test cases.

I\'ve installed Phing with Pear:

Answer 1

Here is a guy with exactly the same problem: How do I tell Phing where PHPUnit is installed?

His theory is that:

PHP version on this machine could be too old and not be able to handle PHAR archives

I can't comment if he is right or not, but that question received no replies from anyone other than the author