ruby on rails：新安装后尝试启动服务器时未定义的方法“version_requirements”答案

【问题标题】：ruby on rails: undefined method "version_requirements' when attempting to start server after new installruby on rails：新安装后尝试启动服务器时未定义的方法“version_requirements”
【发布时间】：2011-03-13 00:00:55
【问题描述】：

我最近不得不在 Rails 上新安装 ruby。当我尝试为在此新安装之前已经在处理的项目启动服务器时，我收到以下错误：

$ ruby script/server
=> Booting WEBrick...
./script/../config/../vendor/rails/railties/lib/rails/gem_dependency.rb:107:in `requirement': undefined method `version_requirements' for #<Gem::Dependency:0xb74bf764> (NoMethodError)
    from ./script/../config/../vendor/rails/railties/lib/initializer.rb:292:in `check_gem_dependencies'
    from ./script/../config/../vendor/rails/railties/lib/initializer.rb:292:in `map'
    from ./script/../config/../vendor/rails/railties/lib/initializer.rb:292:in `check_gem_dependencies'
    from ./script/../config/../vendor/rails/railties/lib/initializer.rb:165:in `process'
from ./script/../config/../vendor/rails/railties/lib/initializer.rb:112:in `send'
    from ./script/../config/../vendor/rails/railties/lib/initializer.rb:112:in `run'
    from /media/78C0-455B/bidmc/schedule/config/environment.rb:13
    from /usr/local/lib/site_ruby/1.8/rubygems/custom_require.rb:36:in `gem_original_require'
    from /usr/local/lib/site_ruby/1.8/rubygems/custom_require.rb:36:in `require'
    from /media/78C0-455B/bidmc/schedule/vendor/rails/activesupport/lib/active_support/dependencies.rb:153:in `require'
    from /media/78C0-455B/bidmc/schedule/vendor/rails/activesupport/lib/active_support/dependencies.rb:521:in `new_constants_in'
    from /media/78C0-455B/bidmc/schedule/vendor/rails/activesupport/lib/active_support/dependencies.rb:153:in `require'
    from /media/78C0-455B/bidmc/schedule/vendor/rails/railties/lib/commands/servers/webrick.rb:59
    from /usr/local/lib/site_ruby/1.8/rubygems/custom_require.rb:36:in `gem_original_require'
    from /usr/local/lib/site_ruby/1.8/rubygems/custom_require.rb:36:in `require'
    from /media/78C0-455B/bidmc/schedule/vendor/rails/activesupport/lib/active_support/dependencies.rb:153:in `require'
    from /media/78C0-455B/bidmc/schedule/vendor/rails/activesupport/lib/active_support/dependencies.rb:521:in `new_constants_in'
    from /media/78C0-455B/bidmc/schedule/vendor/rails/activesupport/lib/active_support/dependencies.rb:153:in `require'
    from /media/78C0-455B/bidmc/schedule/vendor/rails/railties/lib/commands/server.rb:49
    from /usr/local/lib/site_ruby/1.8/rubygems/custom_require.rb:36:in `gem_original_require'
    from /usr/local/lib/site_ruby/1.8/rubygems/custom_require.rb:36:in `require'
    from script/server:3

我有最新版本的 ruby、rubygems 和 rails。

有什么建议吗？

谢谢。

【问题讨论】：

应用程序是用什么版本的 Rails 编写的？也许有一些 gem（供应商或其他）与您安装的 rails 版本不兼容？

标签： ruby-on-rails rubygems installation

【解决方案1】：

看起来您正在使用新版本的 rubygems 和旧版本的 rails。

这里有一个解决方案：https://gist.github.com/807008

【讨论】：