Yes, I have not installed Leopard yet, and not surprised it doesn’t work. It sounds like a number of things have changed with Xcode 3.

When I get 10.5 and Xcode 3 set up I’ll jump on this.

In the meantime, if you have other projects that aren’t working with Xcode 3, and you are so inclined, there is a workaround. Apple has released Xcode 2.5, which can be installed on Leopard along side Xcode 3, so you can use them both.

XAPGen would likely work with 2.5. You can get it here:

http://developer.apple.com/tools/download/

(or you can just use it with Ant)

It seems that this doesn’t work with Xcode 3.0 yet. Just to let you know.
(Getting error “Unable to parse the project file”)

Hopefully this will be fixed at some point so I could test this out.