尝试运行rake cucumber:ok并收到此错误：
/Users/dev/.rbenv/versions/1.9.2-p290/lib/ruby/gems/1.9.1/gems/rack-1.3.4/lib/rack/backports/uri/common_192.rb:53: warning: already initialized constant WFKV_
然后：
Command failed with status (1): [/Users/dev/.rbenv/versions/1.9.2-p290/bin...]
我对Rails很陌生，谷歌没有为此错误做任何改变。
编辑：我已尝试添加bundle exec，这没有任何区别。
以下是我--trace所得到的：
/Users/dev/.rbenv/versions/1.9.2-p290/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/file_utils.rb:53:in `block in create_shell_runner'
/Users/dev/.rbenv/versions/1.9.2-p290/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/file_utils.rb:45:in `call'
/Users/dev/.rbenv/versions/1.9.2-p290/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/file_utils.rb:45:in `sh'
/Users/dev/.rbenv/versions/1.9.2-p290/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/file_utils_ext.rb:36:in `sh'
/Users/dev/.rbenv/versions/1.9.2-p290/lib/ruby/gems/1.9.1/gems/cucumber-1.1.0/lib/cucumber/rake/task.rb:104:in `run'
/Users/dev/.rbenv/versions/1.9.2-p290/lib/ruby/gems/1.9.1/gems/cucumber-1.1.0/lib/cucumber/rake/task.rb:193:in `block in define_task'
/Users/dev/.rbenv/versions/1.9.2-p290/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/task.rb:205:in `call'
/Users/dev/.rbenv/versions/1.9.2-p290/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/task.rb:205:in `block in execute'
/Users/dev/.rbenv/versions/1.9.2-p290/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/task.rb:200:in `each'
/Users/dev/.rbenv/versions/1.9.2-p290/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/task.rb:200:in `execute'
/Users/dev/.rbenv/versions/1.9.2-p290/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/task.rb:158:in `block in invoke_with_call_chain'
/Users/dev/.rbenv/versions/1.9.2-p290/lib/ruby/1.9.1/monitor.rb:201:in `mon_synchronize'
/Users/dev/.rbenv/versions/1.9.2-p290/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/task.rb:151:in `invoke_with_call_chain'
/Users/dev/.rbenv/versions/1.9.2-p290/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/task.rb:144:in `invoke'
/Users/dev/.rbenv/versions/1.9.2-p290/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/application.rb:112:in `invoke_task'
/Users/dev/.rbenv/versions/1.9.2-p290/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/application.rb:90:in `block (2 levels) in top_level'
/Users/dev/.rbenv/versions/1.9.2-p290/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/application.rb:90:in `each'
/Users/dev/.rbenv/versions/1.9.2-p290/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/application.rb:90:in `block in top_level'
/Users/dev/.rbenv/versions/1.9.2-p290/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/application.rb:129:in `standard_exception_handling'
/Users/dev/.rbenv/versions/1.9.2-p290/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/application.rb:84:in `top_level'
/Users/dev/.rbenv/versions/1.9.2-p290/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/application.rb:62:in `block in run'
/Users/dev/.rbenv/versions/1.9.2-p290/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/application.rb:129:in `standard_exception_handling'
/Users/dev/.rbenv/versions/1.9.2-p290/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/application.rb:59:in `run'
/Users/dev/.rbenv/versions/1.9.2-p290/lib/ruby/gems/1.9.1/gems/rake-0.9.2/bin/rake:32:in `<top (required)>'
/Users/dev/.rbenv/versions/1.9.2-p290/bin/rake:19:in `load'
/Users/dev/.rbenv/versions/1.9.2-p290/bin/rake:19:in `<main>'
Tasks: TOP => cucumber:ok
答案 0 :(得分：51)
我今天晚上开始遇到同样的问题。它似乎与Rack 1.3.4有关。我通过将它添加到我的Gemfile中来修复它：
gem 'rack', '1.3.3'
然后跑步：
bundle update rack
顺便说一下，我在此之前尝试过Bozhidar的建议，但无济于事。
答案 1 :(得分：8)
Rack 1.3.5现已推出，已修复此警告。
答案 2 :(得分：0)
您应该卸载rake-0.9.2 并安装机架1.6.13
gem uninstall rake
gem install rack 1.6.13
答案 3 :(得分：-1)
所以，我包括：
要求'uri / common'; :: URI.send：remove_const，：WFKV _
然而，在Gemfile中显示“它将起作用”的评论实际上应该在Gemfile中读取“必须。”