Active_support/dependencies.rb：247`require'：无法加载这样的文件 - 2.1/pg_ext（LoadError）

Question

我在Windows机器上使用Ruby 2.1.5，Rails 4.1.6和PostgreSQL 9.3.5。

当我尝试bundle exec rails server，我结束了以下错误：在更新

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>' 

Answer 1

后，有时会发生。

尝试移除所有宝石并重新安装。像

rm -rf ./vendor/bundle 
bundle install 

Answer 2

我需要使用PG宝石的新版本：

gem 'pg', '~> 0.18.0.pre20141117110243'