无法加载mysql2宝石

Question

我已经看到somedifferentanswers，但这些都不帮我...

这是招：我有解决这个没有接触的Gemfile。我目前正在创建我的工作环境，以便它与生产服务器相匹配，所以我根本无法修改rails的代码。

我的操作系统：OSX 10.11

红宝石：红宝石2.0.0p643

的Rails：4.0.0

创业板的Gemfile中为gem 'mysql2'。做bundle install时，有没有错误，但是当我尝试rake db:migrate --trace这是输出：

rake aborted! 
There was an error while trying to load the gem 'mysql2'. 
/Users/redar/.rvm/gems/ruby-2.0.0-p643/gems/bundler-1.11.2/lib/bundler/runtime.rb:80:in `rescue in block (2 levels) in require' 
/Users/redar/.rvm/gems/ruby-2.0.0-p643/gems/bundler-1.11.2/lib/bundler/runtime.rb:76:in `block (2 levels) in require' 
/Users/redar/.rvm/gems/ruby-2.0.0-p643/gems/bundler-1.11.2/lib/bundler/runtime.rb:72:in `each' 
/Users/redar/.rvm/gems/ruby-2.0.0-p643/gems/bundler-1.11.2/lib/bundler/runtime.rb:72:in `block in require' 
/Users/redar/.rvm/gems/ruby-2.0.0-p643/gems/bundler-1.11.2/lib/bundler/runtime.rb:61:in `each' 
/Users/redar/.rvm/gems/ruby-2.0.0-p643/gems/bundler-1.11.2/lib/bundler/runtime.rb:61:in `require' 
/Users/redar/.rvm/gems/ruby-2.0.0-p643/gems/bundler-1.11.2/lib/bundler.rb:99:in `require' 
/Users/redar/redar/config/application.rb:7:in `<top (required)>' 
/Users/redar/redar/Rakefile:4:in `require' 
/Users/redar/redar/Rakefile:4:in `<top (required)>' 
/Users/redar/.rvm/gems/ruby-2.0.0-p643/gems/rake-10.1.0/lib/rake/rake_module.rb:25:in `load' 
/Users/redar/.rvm/gems/ruby-2.0.0-p643/gems/rake-10.1.0/lib/rake/rake_module.rb:25:in `load_rakefile' 
/Users/redar/.rvm/gems/ruby-2.0.0-p643/gems/rake-10.1.0/lib/rake/application.rb:637:in `raw_load_rakefile' 
/Users/redar/.rvm/gems/ruby-2.0.0-p643/gems/rake-10.1.0/lib/rake/application.rb:94:in `block in load_rakefile' 
/Users/redar/.rvm/gems/ruby-2.0.0-p643/gems/rake-10.1.0/lib/rake/application.rb:165:in `standard_exception_handling' 
/Users/redar/.rvm/gems/ruby-2.0.0-p643/gems/rake-10.1.0/lib/rake/application.rb:93:in `load_rakefile' 
/Users/redar/.rvm/gems/ruby-2.0.0-p643/gems/rake-10.1.0/lib/rake/application.rb:77:in `block in run' 
/Users/redar/.rvm/gems/ruby-2.0.0-p643/gems/rake-10.1.0/lib/rake/application.rb:165:in `standard_exception_handling' 
/Users/redar/.rvm/gems/ruby-2.0.0-p643/gems/rake-10.1.0/lib/rake/application.rb:75:in `run' 
/Users/redar/.rvm/gems/ruby-2.0.0-p643/gems/rake-10.1.0/bin/rake:33:in `<top (required)>' 
/Users/redar/.rvm/gems/ruby-2.0.0-p643/bin/rake:23:in `load' 
/Users/redar/.rvm/gems/ruby-2.0.0-p643/bin/rake:23:in `<main>' 
/Users/redar/.rvm/gems/ruby-2.0.0-p643/bin/ruby_executable_hooks:15:in `eval' 
/Users/redar/.rvm/gems/ruby-2.0.0-p643/bin/ruby_executable_hooks:15:in `<main>' 

我不知道如何解释这一点。 Rakefile有什么问题吗？

而且，这是output from the mkmf.log

---

编辑：这是我的Rake文件的内容，位于MYAPP /文件夹

# Add your own tasks in files placed in lib/tasks ending in .rake, 
# for example lib/tasks/capistrano.rake, and they will automatically be available to Rake. 

require File.expand_path('../config/application', __FILE__) 

MyApp::Application.load_tasks 

Answer 1

尝试

bundle exec rake db:migrate 

这将确保您正在执行“rake db：m igrate“，Gemfile中列出的宝石已加载并可用。如果您在没有“bundle exec”的情况下运行它，那么您可能只能使用可用的系统宝石执行。