Please set up a second instance of trunion on the dev signing server for app signing. There should be two instances of trunion running on the box and listening on different ports when this ticket is complete: the existing one for signing receipts and a new one for signing app manifests.
It looks like we don't have a proper dev environment for signing, so that will be the first step.
This bug is blocking FFOS. Cannot land support for packagd/privileged apps in the marketplace without.
The internal only dev instance is up at http://app-signer.dev.addons.phx1.mozilla.com/.