As I was updating some system files on the server, it tried to install a new trac package... Although it wasn't immediately successful, it is now up and running. So happy result from an unintentional upgrade.

As was just announced on www.php.net, PHP4 will not be supported beyond the end of the year. As a result, we will be diverting all future development efforts to require PHP 5.2 or later. 1.0.x maintenance releases will probably maintain PHP4 compatibility, but we will add a warning in configtest.php. Trunk development heading for a 1.1.0 release will now be PHP 5 only.

For more information, check out the ​Go PHP 5 site.