All of my PHP projects use PHPUnit for unit testing. One of my coworkers just refuses to understand the point of testing. He doesn't get Test Driven Development (TDD), and rarely runs the unit tests for his classes. This means that he frequently breaks my build. I can't force him to change his behavior since he doesn't work for me, but I can change the way my systems work. And I control the Subversion server.
I wanted to force unit tests to pass before allowing submission, but couldn't find anything about running PHPUnit tests in a Subversion pre-commit hook. So I wrote my own. Hopefully this will help someone out there:
To use this, copy it to the hooks directory in your Subversion repository and name it 'pre-commit'. Make sure the paths defined in the script are correct for your system. Make it executable (chmod +x pre-commit).