Script to load a queue and then cause the error 'Error subscribing to queue qtest.broadcast (Bunny::ProtocolError)'

bunny_test.rb

#!/usr/bin/env ruby

require 'rubygems'
require 'bunny'

# Chris Doherty, confused by Bunny::Queue#subscribe semantics.
# run with `ruby bunny_test.rb load` followed by `ruby bunny_test.rb consume`.

class BunnyTest

  def initialize(messaging_host, queues, options = {})
    @bunny = Bunny.new :host => messaging_host, :logging => (options[:logging] || false)
    @bunny.start

    # declare queues.
    @queues = {}
    queues.each do |queue|
      @queues[queue] = @bunny.queue queue, :auto_delete => false, :exclusive => false
    end

    # bind to default exchange. this is a direct exchange: no use for topic or fanout yet.
    @exchange = @bunny.exchange('')
    # @bunny.qos :prefetch_count => 1

    @consumer_tag = "#{$$}-#{self.object_id}"
  end

  def send_msg(routing_key, msg)
    @exchange.publish msg, :key => routing_key
  end

  def fetch(queue)
    output = @queues[queue].pop
    return output
  end

  def fetch_wait(queue)
    @queues[queue].subscribe( :consumer_tag => @consumer_tag ) do |output|
      return output
    end
  end

  def load_queue(count)
    count.times do |i|
      send_msg SEND_KEY, "message -> #{i}, sending pid -> #{$$}"
    end
  end

  def consume_queue(limit=1000)
    10000.times do
      output = fetch_wait RECV_Q
      puts "Received: #{output.inspect}"
    end
  end
end

trap(:INT) { exit! }

SEND_KEY = RECV_Q = "qtest.broadcast"

worker = BunnyTest.new 'localhost', RECV_Q

case ARGV[0]
when "load"
  worker.load_queue 10
when "consume"
  worker.consume_queue
else
  puts "'load' or 'consume' only."
end

bunny_test_error.txt

Received: {:header=>#<Qrack::Protocol::Header:0x1080b1248 @weight=0, @properties={:content_type=>"application/octet-stream", :delivery_mode=>1, :priority=>0}, @size=34, @klass=Qrack::Protocol::Basic>, :payload=>"message -> 0, sending pid -> 23355", :delivery_details=>{:consumer_tag=>"23388-2213936240", :exchange=>"", :delivery_tag=>1, :routing_key=>"qtest.broadcast", :redelivered=>false}}
/Users/randomcamel/.rbenv/versions/1.8.7-p352/lib/ruby/gems/1.8/gems/bunny-0.7.8/lib/bunny/client08.rb:81:in `check_response': Error subscribing to queue qtest.broadcast (Bunny::ProtocolError)
        from /Users/randomcamel/.rbenv/versions/1.8.7-p352/lib/ruby/gems/1.8/gems/bunny-0.7.8/lib/bunny/subscription08.rb:80:in `setup_consumer'
        from /Users/randomcamel/.rbenv/versions/1.8.7-p352/lib/ruby/gems/1.8/gems/bunny-0.7.8/lib/qrack/subscription.rb:53:in `consume'
        from /Users/randomcamel/.rbenv/versions/1.8.7-p352/lib/ruby/gems/1.8/gems/bunny-0.7.8/lib/bunny/queue08.rb:311:in `subscribe'
        from qtest.rb:35:in `fetch_wait'
        from qtest.rb:49:in `consume_queue'
        from qtest.rb:48:in `times'
        from qtest.rb:48:in `consume_queue'
        from qtest.rb:65