`assert_index'：没有这样的中间件插入之前：“Rack::Sendfile”

Question

克隆我的存储库时，它从我正在开发它的目录中工作，我收到一个错误。奇怪的是它使用了相同版本的 Ruby 和相同的 Gemset，但我感觉这个错误仍然来自 Gems 的错误。任何人都知道可能是什么原因造成的？有我的宝石：

source 'https://rubygems.org'

gem 'rails', '3.2.2'
gem 'mysql2'
gem 'activeadmin'

group :assets do
  gem 'sass-rails',   '~> 3.2.3'
  gem 'coffee-rails', '~> 3.2.1'
  gem 'uglifier', '>= 1.0.3'
end

gem 'jquery-rails'

错误如下：

eml/orchid → master rails s
=> Booting WEBrick
=> Rails 3.2.2 application starting in development on http://0.0.0.0:3000
=> Call with -d to detach
=> Ctrl-C to shutdown server
Exiting
/Users/eml/.rvm/gems/ruby-1.9.3-p125@LampPostDb/gems/actionpack-3.2.2/lib/action_dispatch/middleware/stack.rb:120:in `assert_index': No such middleware to insert before: "Rack::Sendfile" (RuntimeError)
    from /Users/eml/.rvm/gems/ruby-1.9.3-p125@LampPostDb/gems/actionpack-3.2.2/lib/action_dispatch/middleware/stack.rb:83:in `insert'
    from /Users/eml/.rvm/gems/ruby-1.9.3-p125@LampPostDb/gems/railties-3.2.2/lib/rails/configuration.rb:38:in `block in merge_into'
    from /Users/eml/.rvm/gems/ruby-1.9.3-p125@LampPostDb/gems/railties-3.2.2/lib/rails/configuration.rb:37:in `each'
    from /Users/eml/.rvm/gems/ruby-1.9.3-p125@LampPostDb/gems/railties-3.2.2/lib/rails/configuration.rb:37:in `merge_into'
    from /Users/eml/.rvm/gems/ruby-1.9.3-p125@LampPostDb/gems/railties-3.2.2/lib/rails/engine.rb:469:in `app'
    from /Users/eml/.rvm/gems/ruby-1.9.3-p125@LampPostDb/gems/railties-3.2.2/lib/rails/application/finisher.rb:31:in `block in <module:Finisher>'
    from /Users/eml/.rvm/gems/ruby-1.9.3-p125@LampPostDb/gems/railties-3.2.2/lib/rails/initializable.rb:30:in `instance_exec'
    from /Users/eml/.rvm/gems/ruby-1.9.3-p125@LampPostDb/gems/railties-3.2.2/lib/rails/initializable.rb:30:in `run'
    from /Users/eml/.rvm/gems/ruby-1.9.3-p125@LampPostDb/gems/railties-3.2.2/lib/rails/initializable.rb:55:in `block in run_initializers'
    from /Users/eml/.rvm/gems/ruby-1.9.3-p125@LampPostDb/gems/railties-3.2.2/lib/rails/initializable.rb:54:in `each'
    from /Users/eml/.rvm/gems/ruby-1.9.3-p125@LampPostDb/gems/railties-3.2.2/lib/rails/initializable.rb:54:in `run_initializers'
    from /Users/eml/.rvm/gems/ruby-1.9.3-p125@LampPostDb/gems/railties-3.2.2/lib/rails/application.rb:136:in `initialize!'
    from /Users/eml/.rvm/gems/ruby-1.9.3-p125@LampPostDb/gems/railties-3.2.2/lib/rails/railtie/configurable.rb:30:in `method_missing'
    from /Users/eml/Projects/orchid/orchid/config/environment.rb:5:in `<top (required)>'
    from /Users/eml/.rvm/gems/ruby-1.9.3-p125@LampPostDb/gems/activesupport-3.2.2/lib/active_support/dependencies.rb:251:in `require'
    from /Users/eml/.rvm/gems/ruby-1.9.3-p125@LampPostDb/gems/activesupport-3.2.2/lib/active_support/dependencies.rb:251:in `block in require'
    from /Users/eml/.rvm/gems/ruby-1.9.3-p125@LampPostDb/gems/activesupport-3.2.2/lib/active_support/dependencies.rb:236:in `load_dependency'
    from /Users/eml/.rvm/gems/ruby-1.9.3-p125@LampPostDb/gems/activesupport-3.2.2/lib/active_support/dependencies.rb:251:in `require'
    from /Users/eml/Projects/orchid/orchid/config.ru:4:in `block in <main>'
    from /Users/eml/.rvm/gems/ruby-1.9.3-p125@LampPostDb/gems/rack-1.4.1/lib/rack/builder.rb:51:in `instance_eval'
    from /Users/eml/.rvm/gems/ruby-1.9.3-p125@LampPostDb/gems/rack-1.4.1/lib/rack/builder.rb:51:in `initialize'
    from /Users/eml/Projects/orchid/orchid/config.ru:1:in `new'
    from /Users/eml/Projects/orchid/orchid/config.ru:1:in `<main>'
    from /Users/eml/.rvm/gems/ruby-1.9.3-p125@LampPostDb/gems/rack-1.4.1/lib/rack/builder.rb:40:in `eval'
    from /Users/eml/.rvm/gems/ruby-1.9.3-p125@LampPostDb/gems/rack-1.4.1/lib/rack/builder.rb:40:in `parse_file'
    from /Users/eml/.rvm/gems/ruby-1.9.3-p125@LampPostDb/gems/rack-1.4.1/lib/rack/server.rb:200:in `app'
    from /Users/eml/.rvm/gems/ruby-1.9.3-p125@LampPostDb/gems/railties-3.2.2/lib/rails/commands/server.rb:46:in `app'
    from /Users/eml/.rvm/gems/ruby-1.9.3-p125@LampPostDb/gems/rack-1.4.1/lib/rack/server.rb:301:in `wrapped_app'
    from /Users/eml/.rvm/gems/ruby-1.9.3-p125@LampPostDb/gems/rack-1.4.1/lib/rack/server.rb:252:in `start'
    from /Users/eml/.rvm/gems/ruby-1.9.3-p125@LampPostDb/gems/railties-3.2.2/lib/rails/commands/server.rb:70:in `start'
    from /Users/eml/.rvm/gems/ruby-1.9.3-p125@LampPostDb/gems/railties-3.2.2/lib/rails/commands.rb:55:in `block in <top (required)>'
    from /Users/eml/.rvm/gems/ruby-1.9.3-p125@LampPostDb/gems/railties-3.2.2/lib/rails/commands.rb:50:in `tap'
    from /Users/eml/.rvm/gems/ruby-1.9.3-p125@LampPostDb/gems/railties-3.2.2/lib/rails/commands.rb:50:in `<top (required)>'
    from script/rails:6:in `require'
    from script/rails:6:in `<main>'

谢谢！

更新：搞砸了，所以它在初始目录中也不起作用。肯定与某些宝石有关。

UPDATE2：通过 RVM 创建一个新的 gemset 并运行 bundle install，这里是 gems 及其安装版本的概要：

eml/LampPostDb → master rvm --rvmrc --create 1.9.3-p125@railsadmin
eml/LampPostDb → master bundle install
Fetching source index for https://rubygems.org/
Installing rake (0.9.2.2) 
Installing i18n (0.6.0) 
Installing multi_json (1.1.0) 
Installing activesupport (3.2.2) 
Installing builder (3.0.0) 
Installing activemodel (3.2.2) 
Installing erubis (2.7.0) 
Installing journey (1.0.3) 
Installing rack (1.4.1) 
Installing rack-cache (1.2) 
Installing rack-test (0.6.1) 
Installing hike (1.2.1) 
Installing tilt (1.3.3) 
Installing sprockets (2.1.2) 
Installing actionpack (3.2.2) 
Installing mime-types (1.18) 
Installing polyglot (0.3.3) 
Installing treetop (1.4.10) 
Installing mail (2.4.4) 
Installing actionmailer (3.2.2) 
Installing sass (3.1.15) 
Installing bourbon (1.4.0) 
Installing bcrypt-ruby (3.0.1) with native extensions 
Installing orm_adapter (0.0.6) 
Installing rack-ssl (1.3.2) 
Installing json (1.6.5) with native extensions 
Installing rdoc (3.12) 
Installing thor (0.14.6) 
Installing railties (3.2.2) 
Installing warden (1.1.1) 
Installing devise (2.0.4) 
Installing fastercsv (1.5.4) 
Installing formtastic (2.1.1) 
Installing has_scope (0.5.1) 
Installing responders (0.9.0) 
Installing inherited_resources (1.3.1) 
Installing jquery-rails (2.0.1) 
Installing kaminari (0.13.0) 
Installing arel (3.0.2) 
Installing tzinfo (0.3.32) 
Installing activerecord (3.2.2) 
Installing polyamorous (0.5.0) 
Installing meta_search (1.1.3) 
Installing activeresource (3.2.2) 
Using bundler (1.0.21) 
Installing rails (3.2.2) 
Installing activeadmin (0.4.3) 
Installing coffee-script-source (1.2.0) 
Installing execjs (1.3.0) 
Installing coffee-script (2.2.0) 
Installing coffee-rails (3.2.2) 
Installing mysql2 (0.3.11) with native extensions 
Installing sass-rails (3.2.5) 
Installing uglifier (1.2.3) 

Answer 1

当然，我问了这个问题就找到了罪魁祸首。最初我有had found an issue on Github describing a simlar problem，但我没有 compass.rb 初始化程序。我没想到的是我有一个 sass.rb 初始化程序，它包含几乎相同的代码行。

我不完全确定是否可以将整个文件注释掉，或者它是否会导致一堆问题。该应用程序现在启动良好，但未来只能说明。

如果有人有比这更好的答案，我很乐意将他们的答案标记为正确。