Единорог, отображающий ошибки Стойки, деинициализировал постоянную Стойку:: Линт:: REQUEST_METHOD

Я попытался установить Единорога + Nginx на Ubuntu 14.04. Каждый раз, когда к сайту получают доступ (через localhost:8080 или через Nginx), он просто возвращает ошибку пробела 500. Журнал ошибок дает мне следующее:

NameError: uninitialized constant Rack::Lint::REQUEST_METHOD
    /var/lib/gems/1.9.1/gems/rack-1.6.0/lib/rack/lint.rb:298:in `check_env'
    /var/lib/gems/1.9.1/gems/rack-1.6.0/lib/rack/lint.rb:43:in `_call'
    /var/lib/gems/1.9.1/gems/rack-1.6.0/lib/rack/lint.rb:37:in `call'
    /var/lib/gems/1.9.1/gems/rack-1.6.0/lib/rack/showexceptions.rb:24:in `call'
    /var/lib/gems/1.9.1/gems/rack-1.6.0/lib/rack/commonlogger.rb:33:in `call'
    /var/lib/gems/1.9.1/gems/sinatra-1.4.6/lib/sinatra/base.rb:218:in `call'
    /var/lib/gems/1.9.1/gems/rack-1.6.0/lib/rack/chunked.rb:54:in `call'
    /var/lib/gems/1.9.1/gems/rack-1.6.0/lib/rack/content_length.rb:15:in `call'
    /usr/lib/ruby/vendor_ruby/unicorn/http_server.rb:580:in `process_client'
    /usr/lib/ruby/vendor_ruby/unicorn/http_server.rb:660:in `worker_loop'
    /usr/lib/ruby/vendor_ruby/unicorn/http_server.rb:527:in `spawn_missing_workers'
    /usr/lib/ruby/vendor_ruby/unicorn/http_server.rb:153:in `start'
    /usr/bin/unicorn:126:in `<main>'
E, [2015-04-11T11:20:00.945818 #25817] ERROR -- : app error: uninitialized constant Rack::Request::SCRIPT_NAME (NameError)
E, [2015-04-11T11:20:00.945882 #25817] ERROR -- : /var/lib/gems/1.9.1/gems/rack-1.6.0/lib/rack/request.rb:21:in `script_name'
E, [2015-04-11T11:20:00.945904 #25817] ERROR -- : /var/lib/gems/1.9.1/gems/rack-1.6.0/lib/rack/showexceptions.rb:69:in `pretty'
E, [2015-04-11T11:20:00.945926 #25817] ERROR -- : /var/lib/gems/1.9.1/gems/rack-1.6.0/lib/rack/showexceptions.rb:33:in `rescue in call'
E, [2015-04-11T11:20:00.945946 #25817] ERROR -- : /var/lib/gems/1.9.1/gems/rack-1.6.0/lib/rack/showexceptions.rb:24:in `call'
E, [2015-04-11T11:20:00.945964 #25817] ERROR -- : /var/lib/gems/1.9.1/gems/rack-1.6.0/lib/rack/commonlogger.rb:33:in `call'
E, [2015-04-11T11:20:00.945984 #25817] ERROR -- : /var/lib/gems/1.9.1/gems/sinatra-1.4.6/lib/sinatra/base.rb:218:in `call'
E, [2015-04-11T11:20:00.946001 #25817] ERROR -- : /var/lib/gems/1.9.1/gems/rack-1.6.0/lib/rack/chunked.rb:54:in `call'
E, [2015-04-11T11:20:00.946018 #25817] ERROR -- : /var/lib/gems/1.9.1/gems/rack-1.6.0/lib/rack/content_length.rb:15:in `call'
E, [2015-04-11T11:20:00.946034 #25817] ERROR -- : /usr/lib/ruby/vendor_ruby/unicorn/http_server.rb:580:in `process_client'
E, [2015-04-11T11:20:00.946056 #25817] ERROR -- : /usr/lib/ruby/vendor_ruby/unicorn/http_server.rb:660:in `worker_loop'
E, [2015-04-11T11:20:00.946073 #25817] ERROR -- : /usr/lib/ruby/vendor_ruby/unicorn/http_server.rb:527:in `spawn_missing_workers'
E, [2015-04-11T11:20:00.946095 #25817] ERROR -- : /usr/lib/ruby/vendor_ruby/unicorn/http_server.rb:153:in `start'
E, [2015-04-11T11:20:00.946114 #25817] ERROR -- : /usr/bin/unicorn:126:in `<main>'

Какие-либо идеи?