sb@thinkpad pfff % ./pfff_db /usr/local/src/phpunit/PHPUnit
Locking file: /tmp/pfff_db/lockfile.lock
sb@thinkpad pfff % ./pfff_visual -with_info /tmp/pfff_db ~/pfff
Fatal error: exception Unix.Unix_error(20, "stat", "/home/sb/pfff")
Yes you must used pfff_db_light, not pfff_db when building the database.
I've updated some documentation and made a new wiki page specific to PHP:
Hope it solves your problem.
Got it to work now, see http://www.flickr.com/photos/sebastian_bergmann/5077632132/
However, I think that non-PHP files should not show up for a PHP project. Especially the pfff database file should not show up :-)
Nice. I'll add some documentation about how to visualize test code coverage and deadcode. Why I don't see the TOP button in your screenshot ? BTW if you have a small screen, pfff_visual -ss 1 can help.