Topic: Checking functionality in extension manifest?

I'm working on an extension that requires a particular PHP extension; I'd like the manifest's <install> section to do a extension_loaded() call to make sure the PHP extension is installed, but how do I make the installation terminate (with an appropriate error) to prevent installation of the PunBB extension if the PHP extension isn't loaded?

Re: Checking functionality in extension manifest?

Well, by dissecting some other extensions, it seems calling message() interrupts the installation process, thus preventing a successful install.  Judging by the behavior though, I'd imagine that if anyone else wants to do this you might want to do any cleanup (i.e. if you created a database already before testing and calling message, you'll want to remove the database prior to calling message) as it seems message() completely terminates the flow of the script.