Chuck Burgess has posted a guide for developers out there wanting to get their PEAR packages working with phpUnderControl for builds.
there were some things that I had to discover via trial-and-error with regard to the build files, though possibly they are covered in other pUC docs that I didn't check. The "Getting Started" build example is based on a project sandbox pulling code from a Subversion repository, whereas all my PEAR code comes from CVS.
He talks about his config.xml file (how it turned out that the basic one was all he really needed) and configuring the build.xml to run the tests from the correct location. He also mentions some future ideas like making the builds run the install/upgrade commands before running the tests.