ruby-on-rails - 运行 Rails 的服务器时出现问题

Question

我已经能够为我的 rails 应用程序运行服务器，直到今天我输入“rails s”时，它给出了这个错误：

    Bundler could not find compatible versions for gem "bcrypt-ruby":
  In snapshot (Gemfile.lock):
    bcrypt-ruby (3.1.5)

  In Gemfile:
    sorcery (>= 0) ruby depends on
      bcrypt-ruby (>= 3.0) ruby

Running `bundle update` will rebuild your snapshot from scratch, using only
the gems in your Gemfile, which may resolve the conflict.

我运行了“捆绑更新”，它又给了我一个错误

 An error occurred while installing pg (0.17.1), and Bundler cannot continue.
Make sure that `gem install pg -v '0.17.1'` succeeds before bundling.

然后我决定通过输入以下命令来安装 rails

gem install rails --no-ri --no-rdoc

一切运行顺利，但是一旦我运行“rails --version”进行验证，终端就给了我这个错误：

    Bundler could not find compatible versions for gem "bcrypt-ruby":
  In snapshot (Gemfile.lock):
    bcrypt-ruby (3.1.5)

  In Gemfile:
    sorcery (>= 0) ruby depends on
      bcrypt-ruby (>= 3.0) ruby

Running `bundle update` will rebuild your snapshot from scratch, using only
the gems in your Gemfile, which may resolve the conflict.

我不明白我做错了什么。