我按照以下指南在Bluehost上更新了我的红宝石
http://www.haydonryan.com/installing-ruby-2-1-1p76-and-rails-4-0-4-on-bluehost/
http://www.haydonryan.com/rails-4-passenger-and-bluehost-with-a-cameo-from-wordpress/
然后我使用bluehost的指南安装了redmine 如果我通过ssh运行rails，我得到
=＆GT;启动WEBrick
=＆GT; Rails 4.2.4应用程序在localhost 3000上开始开发 =＆GT;运行rails server -h以获取更多启动选项
=＆GT; Ctrl-C关闭服务器
[2015-10-13 06:45:51] INFO WEBrick 1.3.1
[2015-10-13 06:45:51] INFO ruby 2.2.3（2015-08-18）[x86_64-linux]
[2015-10-13 06:45:51] INFO WEBrick :: HTTPServer #start：pid = 19685 port = 3000
但是，如果我从浏览器中打开网址，则会收到以下错误消息。可能是什么导致了这个？
错误消息：无法初始化MySQL客户端库异常 class：RuntimeError应用程序root：/ home / user / rails_apps / redmine 回溯：
＃文件行位置
0 /home/user/ruby/gems/gems/activesupport-4.2.4/lib/active_support/dependencies.rb 要求中的274 1 /home/user/ruby/gems/gems/activesupport-4.2.4/lib/active_support/dependencies.rb 274在块中要求
2 /home/user/ruby/gems/gems/activesupport-4.2.4/lib/active_support/dependencies.rb 240 in load_dependency
3 /home/user/ruby/gems/gems/activesupport-4.2.4/lib/active_support/dependencies.rb 要求中的274 4 /home/user/ruby/gems/gems/mysql2-0.3.20/lib/mysql2.rb 31 in
5 /home/user/ruby/gems/gems/bundler-1.10.6/lib/bundler/runtime.rb 76 in require
6 /home/user/ruby/gems/gems/bundler-1.10.6/lib/bundler/runtime.rb 76块（2级）中的要求
7 /home/user/ruby/gems/gems/bundler-1.10.6/lib/bundler/runtime.rb 72每个中 8 /home/user/ruby/gems/gems/bundler-1.10.6/lib/bundler/runtime.rb 72 in block in require
9 /home/user/ruby/gems/gems/bundler-1.10.6/lib/bundler/runtime.rb每个中的61 10 /home/user/ruby/gems/gems/bundler-1.10.6/lib/bundler/runtime.rb 61 in require
11 /home/user/ruby/gems/gems/bundler-1.10.6/lib/bundler.rb 134 in require
12 /home5/user/rails_apps/redmine/config/application.rb 5 in 13 /home5/user/rails_apps/redmine/config/environment.rb 2 in require
14 /home5/user/rails_apps/redmine/config/environment.rb 2 in 15 config.ru 3 in require
16 config.ru 3 in block in 17 /home/user/ruby/gems/gems/rack-1.6.4/lib/rack/builder.rb 55 in instance_eval
18 /home/user/ruby/gems/gems/rack-1.6.4/lib/rack/builder.rb 55初始化
19 config.ru 1 in new
20 config.ru 1 in 21 /etc/httpd/modules/passenger/lib/phusion_passenger/rack/application_spawner.rb 225 in eval
22 /etc/httpd/modules/passenger/lib/phusion_passenger/rack/application_spawner.rb 225 in load_rack_app
23 /etc/httpd/modules/passenger/lib/phusion_passenger/rack/application_spawner.rb 157在initialize_server中的块中 24 /etc/httpd/modules/passenger/lib/phusion_passenger/utils.rb 563在report_app_init_status中 25 /etc/httpd/modules/passenger/lib/phusion_passenger/rack/application_spawner.rb 154在initialize_server中 26 /etc/httpd/modules/passenger/lib/phusion_passenger/abstract_server.rb 204在start_synchronously
27 /etc/httpd/modules/passenger/lib/phusion_passenger/abstract_server.rb 开始时为180 28 /etc/httpd/modules/passenger/lib/phusion_passenger/rack/application_spawner.rb 129开始时
29 /etc/httpd/modules/passenger/lib/phusion_passenger/spawn_manager.rb 253在spawn_rack_application中的块（2级）中 30 /etc/httpd/modules/passenger/lib/phusion_passenger/abstract_server_collection.rb 132在lookup_or_add中 31 /etc/httpd/modules/passenger/lib/phusion_passenger/spawn_manager.rb spawn_rack_application中的块246 32 /etc/httpd/modules/passenger/lib/phusion_passenger/abstract_server_collection.rb 82在块中同步
33前奏＆gt; 10：同步
34 /etc/httpd/modules/passenger/lib/phusion_passenger/abstract_server_collection.rb 79同步
35 /etc/httpd/modules/passenger/lib/phusion_passenger/spawn_manager.rb spawn_rack_application中的244 36 /etc/httpd/modules/passenger/lib/phusion_passenger/spawn_manager.rb spawn_application中的137 37 /etc/httpd/modules/passenger/lib/phusion_passenger/spawn_manager.rb 275在handle_spawn_application中 38 /etc/httpd/modules/passenger/lib/phusion_passenger/abstract_server.rb 在server_main_loop中为357 39 /etc/httpd/modules/passenger/lib/phusion_passenger/abstract_server.rb 206在start_synchronously
40 / etc / httpd / modules / passenger / helper-scripts / passenger-spawn-server 99 在