我按照指示在rails here中创建了一个基本的juggernaut聊天，但是在运行juggernaut -g juggernaut.yml时出现以下错误：此前的所有步骤都顺利进行。任何帮助将不胜感激。
MacPro:simplechat fred$ juggernaut -g juggernaut.yml
/Users/fred/.rvm/gems/ruby-1.9.2-p180/gems/maccman-juggernaut-0.5.9/lib/juggernaut/server.rb:128: warning: else without rescue is useless
/Users/fred/.rvm/rubies/ruby-1.9.2-p180/lib/ruby/site_ruby/1.9.1/rubygems/custom_require.rb:54:in `require': /Users/fred/.rvm/gems/ruby-1.9.2-p180/gems/maccman-juggernaut-0.5.9/lib/juggernaut/server.rb:122: syntax error, unexpected ':', expecting keyword_then or ',' or ';' or '\n' (SyntaxError)
when :broadcast: broadcast_command
^
/Users/fred/.rvm/gems/ruby-1.9.2-p180/gems/maccman-juggernaut-0.5.9/lib/juggernaut/server.rb:363: syntax error, unexpected keyword_end, expecting $end
from /Users/fred/.rvm/rubies/ruby-1.9.2-p180/lib/ruby/site_ruby/1.9.1/rubygems/custom_require.rb:54:in `require'
from /Users/fred/.rvm/gems/ruby-1.9.2-p180/gems/maccman-juggernaut-0.5.9/lib/juggernaut.rb:157:in `<top (required)>'
from /Users/fred/.rvm/rubies/ruby-1.9.2-p180/lib/ruby/site_ruby/1.9.1/rubygems/custom_require.rb:54:in `require'
from /Users/fred/.rvm/rubies/ruby-1.9.2-p180/lib/ruby/site_ruby/1.9.1/rubygems/custom_require.rb:54:in `require'
from /Users/fred/.rvm/gems/ruby-1.9.2-p180/gems/maccman-juggernaut-0.5.9/bin/juggernaut:3:in `<top (required)>'
from /Users/fred/.rvm/gems/ruby-1.9.2-p180/bin/juggernaut:19:in `load'
from /Users/fred/.rvm/gems/ruby-1.9.2-p180/bin/juggernaut:19:in `<main>'