I and others ran into the following 2 issues:

If you want to test PDO on OS X, you have to compile the pdo core library into php as static module. You can't build it as shared module because of not exported symbol problems (But the latest configure script warns you, if you try to do it
). If any Mac OS X crack knows how to solve that problem, we're glad to here about that. I tried

yesterday different approaches, but nothing really worked or would have needed to many changes in the source code.. In the meantime, we can live with the pdo-core-as-static solution, since the pdo core will be enabled by default in 5.1. More hints about compiling PDO on OS X (especially with 5.0) can be found at Wez' Blog.

The latest HEAD checkouts of PHP (the upcoming 5.1) need at least libxml2 2.6.x (don't really know, what x has to be right now, .0 should be ok, ext/soap needs .3, but libxml2 is currently at .17, therefore it's well advisable to get a more recent one). This is because of the new error handling stuff. libxml2 2.5.11 will most certainly not be

supported anymore in 5.1. We could ifdef-out those new features, but maintaining such code is just a pain.