ruby-on-rails – Active_support / dependencies.rb：247`require’：无法加载此类文件 – 2.

当我尝试捆绑exec rails服务器时,我最终得到以下错误：

DL is deprecated, please use Fiddle
c:/RailsInstaller/Ruby2.1.0/lib/ruby/gems/2.1.0/gems/activesupport-4.1.6/lib/active_support/dependencies.rb:247:in `require': cannot load such file -- 2.1/pg_ext (LoadError)
 from c:/RailsInstaller/Ruby2.1.0/lib/ruby/gems/2.1.0/gems/activesupport-4.1.6/lib/active_support/dependencies.rb:247:in `block in re...re'
 from c:/RailsInstaller/Ruby2.1.0/lib/ruby/gems/2.1.0/gems/activesupport-4.1.6/lib/active_support/dependencies.rb:232:in `load_dependancy'
 from c:/RailsInstaller/Ruby2.1.0/lib/ruby/gems/2.1.0/gems/activesupport-4.1.6/lib/active_support/dependencies.rb:247:in `require'
 from c:/RailsInstaller/Ruby2.1.0/lib/ruby/gems/2.1.0/gems/pg-0.17.1-x86-mingw32/lib/pg.rb:10:in `rescue in <top (required)>'
 from c:/RailsInstaller/Ruby2.1.0/lib/ruby/gems/2.1.0/gems/pg-0.17.1-x86-mingw32/lib/pg.rb:3:in `<top (required)>'
 from c:/RailsInstaller/Ruby2.1.0/lib/ruby/gems/2.1.0/gems/bundler-1.7.7/lib/bundler/runtime.rb:76:in `require'
 from c:/RailsInstaller/Ruby2.1.0/lib/ruby/gems/2.1.0/gems/bundler-1.7.7/lib/bundler/runtime.rb:76:in `block (2 levels) in require'
 from c:/RailsInstaller/Ruby2.1.0/lib/ruby/gems/2.1.0/gems/bundler-1.7.7/lib/bundler/runtime.rb:72:in `each'
 from c:/RailsInstaller/Ruby2.1.0/lib/ruby/gems/2.1.0/gems/bundler-1.7.7/lib/bundler/runtime.rb:72:in `block in require'
 from c:/RailsInstaller/Ruby2.1.0/lib/ruby/gems/2.1.0/gems/bundler-1.7.7/lib/bundler/runtime.rb:61:in `each'
 from c:/RailsInstaller/Ruby2.1.0/lib/ruby/gems/2.1.0/gems/bundler-1.7.7/lib/bundler/runtime.rb:61:in `require'
 from c:/RailsInstaller/Ruby2.1.0/lib/ruby/gems/2.1.0/gems/bundler-1.7.7/lib/bundler.rb:133:in `require'
 from C:/....../config/application.rb:5:in `<top (required)>'
 from c:/RailsInstaller/Ruby2.1.0/lib/ruby/gems/2.1.0/gems/railties-4.1.6/lib/rails/commands/commands_tasks.rb:79:in `require'
 from c:/RailsInstaller/Ruby2.1.0/lib/ruby/gems/2.1.0/gems/railties-4.1.6/lib/rails/commands/commands_tasks.rb:79:in `block in server
 from c:/RailsInstaller/Ruby2.1.0/lib/ruby/gems/2.1.0/gems/railties-4.1.6/lib/rails/commands/commands_tasks.rb:76:in `tap'
 from c:/RailsInstaller/Ruby2.1.0/lib/ruby/gems/2.1.0/gems/railties-4.1.6/lib/rails/commands/commands_tasks.rb:76:in `server'
 from c:/RailsInstaller/Ruby2.1.0/lib/ruby/gems/2.1.0/gems/railties-4.1.6/lib/rails/commands/commands_tasks.rb:40:in `run_command!'
 from c:/RailsInstaller/Ruby2.1.0/lib/ruby/gems/2.1.0/gems/railties-4.1.6/lib/rails/commands.rb:17:in `<top (required)>'
 from bin/rails:8:in `require'
 from bin/rails:8:in `<main>'

宝石’pg’,’〜> 0.18.0.pre20141117110243′