bundle exec rake db:migrate rake aborted! 126: 找不到指定的模块。 - g:/RailsInstaller/Ruby2.0.0/lib/ruby/gems/2.0.0/gems/bcrypt-ruby-3.1.1-x86-mingw32/lib/bcrypt_ext.so e:/rails/pad/config/boot.rb:8:in `' Tasks: TOP => dm:migrate:up => dm:migrate:load => environment (See full trace by running task with --trace)
哪里可以找到 bcrypt_ext.so 这个文件?