ActionController::RoutingError: No route matches - ruby-on-rails

Question

I am a bit of a freshman in rails, so please bear with me.
I get a routing error on my tests. The tests are as follwoing:
require 'spec_helper'
describe "ProducerPages" do
subject { page }
describe "profile page" do
#producer = Producer.create(name:"Example Producer",
email: "producer#example.com", password: "foobar",
password_confirmation: "foobar")
before { visit producer_path(#producer) }
it { should have_selector('h1', text: producer.name) }
it { should have_selector('title', text: producer.name) }
end
end
and the failure produced is:
Failures:
1) ProducerPages profile page
Failure/Error: before { visit producer_path(#producer) }
ActionController::RoutingError:
No route matches {:action=>"show", :controller=>"producers", :id=>nil}
# ./spec/requests/producer_pages_spec.rb:14:in `block (3 levels) in <top (required)>'
It looks, I do something wrong with creating the producer instance variable. I tried to make that a normal variable, but then I get this error:
1) ProducerPages profile page
Failure/Error: before { visit producer_path(producer) }
ActionController::RoutingError:
No route matches {:action=>"show", :controller=>"producers",
:id=>#<Producer id: nil, name: "Example Producer",
email: "producer#example.com", created_at: nil, updated_at: nil,
password_digest: "$2a$04$pXAEklj4nzYe48ojR5Ps/Oh8Ea9.QqKOajYBD2Rv0mQ9...",
remember_token: nil, admin: false, oid: nil, contact_name: nil,
street: nil, postal_code: nil, city: nil, country: nil, url: nil,
telephone: nil, cellular: nil, type: "Producer", producer_id: nil,
client_key: nil, product_count: 0>}
# ./spec/requests/producer_pages_spec.rb:14:in `block (3 levels) in <top (required)>'
the routes.rb file contains
resources :producers
What am I doing wrong?