ruby-on-rails - 更新 gem 后出现 Rails 错误

Question

运行 gem update 后，当我尝试启动 rails 时出现以下错误:

$ rails s
/usr/lib/ruby/1.9.1/rubygems.rb:238:in `activate': can't activate rack (~> 1.4.5, runtime)
for ["actionpack-3.2.12", "railties-3.2.12"], already activated rack-1.5.2 for ["rack-
ssl-1.3.3", "railties-3.2.12"] (Gem::LoadError)
    from /usr/lib/ruby/1.9.1/rubygems.rb:254:in `block in activate'
    from /usr/lib/ruby/1.9.1/rubygems.rb:253:in `each'
    from /usr/lib/ruby/1.9.1/rubygems.rb:253:in `activate'
    from /usr/lib/ruby/1.9.1/rubygems.rb:254:in `block in activate'
    from /usr/lib/ruby/1.9.1/rubygems.rb:253:in `each'
    from /usr/lib/ruby/1.9.1/rubygems.rb:253:in `activate'
    from /usr/lib/ruby/1.9.1/rubygems.rb:1065:in `gem'
    from /usr/local/bin/rails:18:in `<main>'

谁能帮帮我，这是什么意思，如何解决这个问题？

Answer 1

您必须使用 bundler 运行它。

$ bundle exec rails s

否则需要卸载机架1.5.2版本。