ruby-on-rails之bundle 命令错误的 mysql2 gem(总是 0.3.2)

尝试运行 $rails 控制台时出现错误

/Library/Ruby/Gems/1.8/gems/mysql2-0.3.2/lib/mysql2/mysql2.bundle: dlopen(/Library/Ruby/Gems/1.8/gems/mysql2-0.3.2/lib/mysql2/mysql2.bundle, 9): Library not loaded: libmysqlclient.16.dylib (LoadError) 
  Referenced from: /Library/Ruby/Gems/1.8/gems/mysql2-0.3.2/lib/mysql2/mysql2.bundle 
  Reason: image not found - /Library/Ruby/Gems/1.8/gems/mysql2-0.3.2/lib/mysql2/mysql2.bundle 
    from /Library/Ruby/Gems/1.8/gems/mysql2-0.3.2/lib/mysql2.rb:8 
    from /Library/Ruby/Gems/1.8/gems/bundler-1.0.7/lib/bundler/runtime.rb:64:in `require' 
    from /Library/Ruby/Gems/1.8/gems/bundler-1.0.7/lib/bundler/runtime.rb:64:in `require' 
    from /Library/Ruby/Gems/1.8/gems/bundler-1.0.7/lib/bundler/runtime.rb:62:in `each' 
    from /Library/Ruby/Gems/1.8/gems/bundler-1.0.7/lib/bundler/runtime.rb:62:in `require' 
    from /Library/Ruby/Gems/1.8/gems/bundler-1.0.7/lib/bundler/runtime.rb:51:in `each' 
    from /Library/Ruby/Gems/1.8/gems/bundler-1.0.7/lib/bundler/runtime.rb:51:in `require' 
    from /Library/Ruby/Gems/1.8/gems/bundler-1.0.7/lib/bundler.rb:112:in `require' 
    from /Users/ccool2486/Sites/test3mysql/config/application.rb:7 
    from /Library/Ruby/Gems/1.8/gems/railties-3.0.6/lib/rails/commands.rb:21:in `require' 
    from /Library/Ruby/Gems/1.8/gems/railties-3.0.6/lib/rails/commands.rb:21 
    from script/rails:6:in `require' 
    from script/rails:6 
ccool-2:test3mysql ccool2486$ rails console 
WARNING: This version of mysql2 (0.3.2) doesn't ship with the ActiveRecord adapter bundled anymore as it's now part of Rails 3.1 
WARNING: Please use the 0.2.x releases if you plan on using it in Rails <= 3.0.x 
/Library/Ruby/Gems/1.8/gems/activerecord-3.0.6/lib/active_record/connection_adapters/abstract/connection_specification.rb:71:in `establish_connection': Please install the mysql2 adapter: `gem install activerecord-mysql2-adapter` (no such file to load -- active_record/connection_adapters/mysql2_adapter) (RuntimeError) 
    from /Library/Ruby/Gems/1.8/gems/activerecord-3.0.6/lib/active_record/connection_adapters/abstract/connection_specification.rb:60:in `establish_connection' 
    from /Library/Ruby/Gems/1.8/gems/activerecord-3.0.6/lib/active_record/connection_adapters/abstract/connection_specification.rb:55:in `establish_connection' 
    from /Library/Ruby/Gems/1.8/gems/activerecord-3.0.6/lib/active_record/railtie.rb:59 
    from /Library/Ruby/Gems/1.8/gems/activesupport-3.0.6/lib/active_support/lazy_load_hooks.rb:36:in `instance_eval' 
    from /Library/Ruby/Gems/1.8/gems/activesupport-3.0.6/lib/active_support/lazy_load_hooks.rb:36:in `execute_hook' 
    from /Library/Ruby/Gems/1.8/gems/activesupport-3.0.6/lib/active_support/lazy_load_hooks.rb:43:in `run_load_hooks' 
    from /Library/Ruby/Gems/1.8/gems/activesupport-3.0.6/lib/active_support/lazy_load_hooks.rb:42:in `each' 
    from /Library/Ruby/Gems/1.8/gems/activesupport-3.0.6/lib/active_support/lazy_load_hooks.rb:42:in `run_load_hooks' 
    from /Library/Ruby/Gems/1.8/gems/activerecord-3.0.6/lib/active_record/base.rb:1903 
    from /Library/Ruby/Gems/1.8/gems/activerecord-3.0.6/lib/active_record/railtie.rb:32 
    from /Library/Ruby/Gems/1.8/gems/activesupport-3.0.6/lib/active_support/dependencies.rb:239:in `call' 
    from /Library/Ruby/Gems/1.8/gems/activesupport-3.0.6/lib/active_support/dependencies.rb:239:in `to_proc' 
    from /Library/Ruby/Gems/1.8/gems/railties-3.0.6/lib/rails/railtie.rb:180:in `each' 
    from /Library/Ruby/Gems/1.8/gems/railties-3.0.6/lib/rails/railtie.rb:180:in `load_console' 
    from /Library/Ruby/Gems/1.8/gems/railties-3.0.6/lib/rails/application.rb:154:in `load_console' 
    from /Library/Ruby/Gems/1.8/gems/railties-3.0.6/lib/rails/application/railties.rb:11:in `each' 
    from /Library/Ruby/Gems/1.8/gems/railties-3.0.6/lib/rails/application/railties.rb:11:in `all' 
    from /Library/Ruby/Gems/1.8/gems/railties-3.0.6/lib/rails/application.rb:154:in `load_console' 
    from /Library/Ruby/Gems/1.8/gems/railties-3.0.6/lib/rails/commands/console.rb:26:in `start' 
    from /Library/Ruby/Gems/1.8/gems/railties-3.0.6/lib/rails/commands/console.rb:8:in `start' 
    from /Library/Ruby/Gems/1.8/gems/railties-3.0.6/lib/rails/commands.rb:23 
    from script/rails:6:in `require' 
    from script/rails:6 

嗯...所以我尝试卸载 mysql2 gem，并重新安装版本 0.2.7 gem

 sudo gem uninstall mysql2 -i /Library/Ruby/Gems/1.8 

我更改了 gemfile:

gem 'mysql2','0.2.7' 

在我的应用目录中运行 Bundler:

bundle install 

但它又重新安装了 0.3.2 版!!!谁能帮忙，老实说我不知道​​这里发生了什么。

请您参考如下方法:

sudo gem uninstall mysql2 

在 Gemfile gem 'mysql2', '< 0.3'

bundle update