没有这样的文件来加载active_record / associations / has_and_belongs_to_many_association
我在我的Gemfile中添加了composite_primary_keys gem。 在本地环境中运行良好，但在centos机器上它会出现以下错误。 Ruby环境版本为1.9.2p290，rubygems版本为1.3.7。 有谁知道为什么会这样？
bundle exec rake db:create --trace no such file to load -- active_record/associations/has_and_belongs_to_many_association /var/tmp/jenkins/gem_cache/myapp/gems/activesupport-3.1.3/lib/active_support/dependencies.rb:240:in `require' /var/tmp/jenkins/gem_cache/myapp/gems/activesupport-3.1.3/lib/active_support/dependencies.rb:240:in `block in require' /var/tmp/jenkins/gem_cache/myapp/gems/activesupport-3.1.3/lib/active_support/dependencies.rb:223:in `block in load_dependency' /var/tmp/jenkins/gem_cache/myapp/gems/activesupport-3.1.3/lib/active_support/dependencies.rb:640:in `new_constants_in' /var/tmp/jenkins/gem_cache/myapp/gems/activesupport-3.1.3/lib/active_support/dependencies.rb:223:in `load_dependency' /var/tmp/jenkins/gem_cache/myapp/gems/activesupport-3.1.3/lib/active_support/dependencies.rb:240:in `require' /var/tmp/jenkins/gem_cache/myapp/gems/composite_primary_keys-4.1.2/lib/composite_primary_keys.rb:40:in `' /opt/ruby/1.9.2/lib/ruby/gems/1.9.1/gems/bundler-1.0.22/lib/bundler/runtime.rb:68:in `require' /opt/ruby/1.9.2/lib/ruby/gems/1.9.1/gems/bundler-1.0.22/lib/bundler/runtime.rb:68:in `block (2 levels) in require' /opt/ruby/1.9.2/lib/ruby/gems/1.9.1/gems/bundler-1.0.22/lib/bundler/runtime.rb:66:in `each' /opt/ruby/1.9.2/lib/ruby/gems/1.9.1/gems/bundler-1.0.22/lib/bundler/runtime.rb:66:in `block in require' /opt/ruby/1.9.2/lib/ruby/gems/1.9.1/gems/bundler-1.0.22/lib/bundler/runtime.rb:55:in `each' /opt/ruby/1.9.2/lib/ruby/gems/1.9.1/gems/bundler-1.0.22/lib/bundler/runtime.rb:55:in `require' /opt/ruby/1.9.2/lib/ruby/gems/1.9.1/gems/bundler-1.0.22/lib/bundler.rb:122:in `require' 尝试将Composite_primary_keys gem与Active Record 4.1.0一起使用时，可能会发生同样的错误：
.../vendor/cache/ruby/1.9.1/gems/activesupport-4.1.0/lib/active_support/dependencies.rb:247:in `require': cannot load such file -- active_record/associations/has_and_belongs_to_many_association (LoadError) from .../vendor/cache/ruby/1.9.1/gems/activesupport-4.1.0/lib/active_support/dependencies.rb:247:in `block in require' from .../vendor/cache/ruby/1.9.1/gems/activesupport-4.1.0/lib/active_support/dependencies.rb:232:in `load_dependency' ...
这是因为当前发布的composite_primary_keys（截至2014年4月17日的版本6.0.1）不包括对Active Record 4.1.0的支持，Active Record 4.1.0显然删除了相关文件。
然而，问题在gem的源代码的ar_4.1.x分支中得到修复。 如果您的项目使用Bundler，则解决方案是编辑其Gemfile并替换该行
gem 'composite_primary_keys'
同
gem 'composite_primary_keys', { :git => 'git://github.com/composite-primary-keys/composite_primary_keys.git', :branch => 'ar_4.1.x' }
然后从项目的根文件夹运行bundle install 。
清理jenkins机器上的共享gem列表修复了该问题。
更新你的Gemfile：gem’composite_primary_keys gem 'composite_primary_keys', '~> 7.0'