Regarding the hub package (cfengine-nova-hub), the current version (Enterprise 3.5.1) of Debian 6 is running fine on Debian 7 machine. There was a PHP compat problem on 3.0 but since we compile everything and package up on our own, we have managed to get rid of this incompatibility problem. Please feel free to use the package and run on Debian 7 machine.
You may download packages from here,
Enterprise Software Download,