我正在尝试在我的 Fedora 机器上安装 Redmine，我一直在关注官方 wiki 来安装它，当我被要求运行
*rake generate_secret_token*
命令，但是当我这样做时，我得到了这个错误
rake aborted!
cannot load such file -- mysql2/mysql2
/home/usera/redmine-2.3/config/application.rb:7:in `<top (required)>'
/home/usera/redmine-2.3/Rakefile:5:in `<top (required)>'
(See full trace by running task with --trace)
与 --trace
rake aborted!
cannot load such file -- mysql2/mysql2
/usr/local/share/gems/gems/mysql2-0.3.13/lib/mysql2.rb:8:in `require'
/usr/local/share/gems/gems/mysql2-0.3.13/lib/mysql2.rb:8:in `<top (required)>'
/usr/local/share/gems/gems/bundler-1.3.5/lib/bundler/runtime.rb:72:in `require'
/usr/local/share/gems/gems/bundler-1.3.5/lib/bundler/runtime.rb:72:in `block (2 levels) in require'
/usr/local/share/gems/gems/bundler-1.3.5/lib/bundler/runtime.rb:70:in `each'
/usr/local/share/gems/gems/bundler-1.3.5/lib/bundler/runtime.rb:70:in `block in require'
/usr/local/share/gems/gems/bundler-1.3.5/lib/bundler/runtime.rb:59:in `each'
/usr/local/share/gems/gems/bundler-1.3.5/lib/bundler/runtime.rb:59:in `require'
/usr/local/share/gems/gems/bundler-1.3.5/lib/bundler.rb:132:in `require'
/home/usera/redmine-2.3/config/application.rb:7:in `<top (required)>'
/usr/share/rubygems/rubygems/custom_require.rb:36:in `require'
/usr/share/rubygems/rubygems/custom_require.rb:36:in `require'
/home/usera/redmine-2.3/Rakefile:5:in `<top (required)>'
/usr/local/share/gems/gems/rake-10.1.0/lib/rake/rake_module.rb:25:in `load'
/usr/local/share/gems/gems/rake-10.1.0/lib/rake/rake_module.rb:25:in `load_rakefile'
/usr/local/share/gems/gems/rake-10.1.0/lib/rake/application.rb:637:in `raw_load_rakefile'
/usr/local/share/gems/gems/rake-10.1.0/lib/rake/application.rb:94:in `block in load_rakefile'
/usr/local/share/gems/gems/rake-10.1.0/lib/rake/application.rb:165:in `standard_exception_handling'
/usr/local/share/gems/gems/rake-10.1.0/lib/rake/application.rb:93:in `load_rakefile'
/usr/local/share/gems/gems/rake-10.1.0/lib/rake/application.rb:77:in `block in run'
/usr/local/share/gems/gems/rake-10.1.0/lib/rake/application.rb:165:in `standard_exception_handling'
/usr/local/share/gems/gems/rake-10.1.0/lib/rake/application.rb:75:in `run'
/usr/local/share/gems/gems/rake-10.1.0/bin/rake:33:in `<top (required)>'
/bin/rake:23:in `load'
/bin/rake:23:in `<main>'
我以 root 身份运行该命令。这是我使用的指南http://www.redmine.org/projects/redmine/wiki/RedmineInstall