Knife client outputs nothing on attempted client key generation when there is a conflict

Running knife -i to try and generate a knife config file and local client.pem file (validation and webui.pems present)

The knife client Appears to succeed with all the correct messages about successful generation.
On opening client.pem it is completely empty.

This is due to the server throwing:

Client already exists - (Merb::ControllerExceptions::Conflict)
/usr/share/chef-server-api/app/controllers/clients.rb:66:in `create'
/usr/lib/ruby/1.8/merb-core/controller/abstract_controller.rb:315:in `send'
/usr/lib/ruby/1.8/merb-core/controller/abstract_controller.rb:315:in `_call_action'
/usr/lib/ruby/1.8/merb-core/controller/abstract_controller.rb:289:in `_dispatch'
/usr/lib/ruby/1.8/merb-core/controller/merb_controller.rb:252:in `_dispatch'
/usr/lib/ruby/1.8/merb-core/dispatch/dispatcher.rb:102:in `dispatch_action'

There are good reasons why the client already exists, although I don't have it locally.
However, a nicer error message on the knife client side would be nice, so I don't have to go debugging points in the system to find out what's wrong.

Thanks