Could not find gem 'sqlite3 (>= 0) x64-mingw32' in any of the gem sources listed in your Gemfile or available on this machine.  

Run `bundle install` to install missing gems. 

在 windows下搭建Ruby Rails Web开发环境 时遇到这个问题，

出现此问题的原因是：没有安装sqlite3

安装sqlite3

执行命令：gem install sqlite3-ruby

安装过程中可能会出现以下问题：

Could not find gem 'sqlite3 (>= 0) x64-mingw32' in any of the gem sources listed in your Gemfile or available on this machine.  
Run `bundle install` to install missing gems. 
" port 443 (https://api.rubygems.org/quick/Marshal.4.8/sqlite3-ruby-1.3.3.gemspec.rz)

这可能是由于网络的原因，多试几次就好了。