我正在关注 edX 的 SaaS，我正在尝试运行我使用创建的 Rails 服务器
rails s
它不断抛出一个加载错误
gem/ruby-1.9.3-p448/gems/ruby-debug-base19-0.11.25/lib/ruby_debug.so:
undefined symbol: ruby_current_thread
我不太确定我能做些什么来解决这个问题，或者需要什么其他信息来帮助我解决这个问题。对于这样一个模糊的帖子，我很抱歉，但是 ruby on rails 对我来说相当新，我不知道为什么它会抛出这个
我试过了
gem install rails
我得到一个权限错误
*编辑 1
Gemfile debug19 是我被告知按照 edX 169.1 的指示放入的
source 'https://rubygems.org'
gem 'rails', '3.2.14'
# Bundle edge Rails instead:
# gem 'rails', :git => 'git://github.com/rails/rails.git'
gem 'sqlite3'
# Gems used only for assets and not required
# in production environments by default.
group :assets do
gem 'sass-rails', '~> 3.2.3'
gem 'coffee-rails', '~> 3.2.1'
# See https://github.com/sstephenson/execjs#readme for more supported runtimes
# gem 'therubyracer', :platforms => :ruby
gem 'uglifier', '>= 1.0.3'
end
gem 'jquery-rails'
# To use ActiveModel has_secure_password
# gem 'bcrypt-ruby', '~> 3.0.0'
# To use Jbuilder templates for JSON
# gem 'jbuilder'
# Use unicorn as the app server
# gem 'unicorn'
# Deploy with Capistrano
# gem 'capistrano'
gem 'haml'
# To use debugger
# gem 'debugger'
group :development ,:test do
gem 'ruby-debug19' , :require => 'ruby-debug'
end