Debian is not a supported platform for Chef Server at this time. Adding new platform support is not something I would recommend if you don’t want to learn Erlang. That said, the error is more likely in one of the rebar configs than something related to Debian.
Looks like a winner! I’m not in a position to test the resulting .deb right now, but I have a successful build after merging 7e66f25 from above. Thanks!