If there's nothing to create the debuginfo package from and the package can't be noarch, I suppose the debuginfo package should just be disabled with "%global debug_package %{nil}". See bug 496968 for more info.
Fix has been made and build submitted to rawhide.
The problem has resurfaced in 3.1-1.fc12.
The package is no longer arch specific because it does not require CDT. I took out the BuildArch statement when I should have specified noarch. There should be no debuginfo for the package. I have just submitted 3.1-2 to rawhide.