Hello, I have worked on solutions to debug php-gtk recently, and it had a major result : php-gtk2 2.0.1 needs a debugger working in php 5.2 not thread safe. No debugger had such a version recently, but now Xdebug has one (see www.xdebug.org). It works fine with NetBeans. Perhaps it would be a good choice for Geany as well ? If Geanydebug just starts its development, this option could be considered since Xdebug is open source and works fine for php-gtk2. But I have not made any test of deugging with Geany, I am working with the developper of DevPhp.
Dysmas