Librato stack trace

gistfile1.txt

/Users/pro/.rvm/gems/ruby-1.9.3-p194/gems/activesupport-3.1.3/lib/active_support/whiny_nil.rb:48:in `method_missing': undefined method `keys' for nil:NilClass (NoMethodError)
	from /Users/pro/.rvm/gems/ruby-1.9.3-p194/bundler/gems/librato-rails-7fdb0ec65cb2/lib/librato/rails.rb:57:in `check_config'
	from /Users/pro/.rvm/gems/ruby-1.9.3-p194/bundler/gems/librato-rails-7fdb0ec65cb2/lib/librato/rails.rb:111:in `setup'
	from /Users/pro/.rvm/gems/ruby-1.9.3-p194/bundler/gems/librato-rails-7fdb0ec65cb2/lib/librato/rails/railtie.rb:11:in `block in <class:Railtie>'
	from /Users/pro/.rvm/gems/ruby-1.9.3-p194/gems/railties-3.1.3/lib/rails/initializable.rb:30:in `instance_exec'
	from /Users/pro/.rvm/gems/ruby-1.9.3-p194/gems/railties-3.1.3/lib/rails/initializable.rb:30:in `run'
	from /Users/pro/.rvm/gems/ruby-1.9.3-p194/gems/railties-3.1.3/lib/rails/initializable.rb:55:in `block in run_initializers'
	from /Users/pro/.rvm/gems/ruby-1.9.3-p194/gems/railties-3.1.3/lib/rails/initializable.rb:54:in `each'
	from /Users/pro/.rvm/gems/ruby-1.9.3-p194/gems/railties-3.1.3/lib/rails/initializable.rb:54:in `run_initializers'
	from /Users/pro/.rvm/gems/ruby-1.9.3-p194/gems/railties-3.1.3/lib/rails/application.rb:96:in `initialize!'
	from /Users/pro/.rvm/gems/ruby-1.9.3-p194/gems/railties-3.1.3/lib/rails/railtie/configurable.rb:30:in `method_missing'
	from /Users/pro/dev/my/my_app/config/environment.rb:5:in `<top (required)>'
	from /Users/pro/.rvm/gems/ruby-1.9.3-p194/gems/activesupport-3.1.3/lib/active_support/dependencies.rb:240:in `require'
	from /Users/pro/.rvm/gems/ruby-1.9.3-p194/gems/activesupport-3.1.3/lib/active_support/dependencies.rb:240:in `block in require'
	from /Users/pro/.rvm/gems/ruby-1.9.3-p194/gems/activesupport-3.1.3/lib/active_support/dependencies.rb:223:in `block in load_dependency'
	from /Users/pro/.rvm/gems/ruby-1.9.3-p194/gems/activesupport-3.1.3/lib/active_support/dependencies.rb:640:in `new_constants_in'
	from /Users/pro/.rvm/gems/ruby-1.9.3-p194/gems/activesupport-3.1.3/lib/active_support/dependencies.rb:223:in `load_dependency'
	from /Users/pro/.rvm/gems/ruby-1.9.3-p194/gems/activesupport-3.1.3/lib/active_support/dependencies.rb:240:in `require'
	from /Users/pro/dev/my/my_app/config.ru:4:in `block in <main>'
	from /Users/pro/.rvm/gems/ruby-1.9.3-p194/gems/rack-1.3.6/lib/rack/builder.rb:51:in `instance_eval'
	from /Users/pro/.rvm/gems/ruby-1.9.3-p194/gems/rack-1.3.6/lib/rack/builder.rb:51:in `initialize'
	from /Users/pro/dev/my/my_app/config.ru:1:in `new'
	from /Users/pro/dev/my/my_app/config.ru:1:in `<main>'
	from /Users/pro/.rvm/gems/ruby-1.9.3-p194/gems/rack-1.3.6/lib/rack/builder.rb:40:in `eval'
	from /Users/pro/.rvm/gems/ruby-1.9.3-p194/gems/rack-1.3.6/lib/rack/builder.rb:40:in `parse_file'
	from /Users/pro/.rvm/gems/ruby-1.9.3-p194/gems/rack-1.3.6/lib/rack/server.rb:200:in `app'
	from /Users/pro/.rvm/gems/ruby-1.9.3-p194/gems/railties-3.1.3/lib/rails/commands/server.rb:46:in `app'
	from /Users/pro/.rvm/gems/ruby-1.9.3-p194/gems/rack-1.3.6/lib/rack/server.rb:301:in `wrapped_app'
	from /Users/pro/.rvm/gems/ruby-1.9.3-p194/gems/rack-1.3.6/lib/rack/server.rb:252:in `start'
	from /Users/pro/.rvm/gems/ruby-1.9.3-p194/gems/railties-3.1.3/lib/rails/commands/server.rb:70:in `start'
	from /Users/pro/.rvm/gems/ruby-1.9.3-p194/gems/railties-3.1.3/lib/rails/commands.rb:54:in `block in <top (required)>'
	from /Users/pro/.rvm/gems/ruby-1.9.3-p194/gems/railties-3.1.3/lib/rails/commands.rb:49:in `tap'
	from /Users/pro/.rvm/gems/ruby-1.9.3-p194/gems/railties-3.1.3/lib/rails/commands.rb:49:in `<top (required)>'
	from script/rails:6:in `require'
	from script/rails:6:in `<main>'