Ruby on rails 3.2 使用mongoid启动rails服务器时出错

昨天，我的项目仍然正常工作。但是，今天我重新安装了操作系统。我的项目不起作用。我无法运行命令：rails s。当我运行命令时：rails s

==>结果

Usage:
  rails new APP_PATH [options]

Options:
  -r, [--ruby=PATH]                                      # Path to the Ruby binary of your choice
                                                         # Default: /home/khaihkd/.rvm/rubies/ruby-2.0.0-p451/bin/ruby
  -m, [--template=TEMPLATE]                              # Path to some application template (can be a filesystem path or URL)
      [--skip-gemfile], [--no-skip-gemfile]              # Don't create a Gemfile
  -B, [--skip-bundle], [--no-skip-bundle]                # Don't run bundle install
  -G, [--skip-git], [--no-skip-git]                      # Skip .gitignore file
      [--skip-keeps], [--no-skip-keeps]                  # Skip source control .keep files
  -O, [--skip-active-record], [--no-skip-active-record]  # Skip Active Record files
  -S, [--skip-sprockets], [--no-skip-sprockets]          # Skip Sprockets files
  -d, [--database=DATABASE]                              # Preconfigure for selected database (options: mysql/oracle/postgresql/sqlite3/frontbase/ibm_db/sqlserver/jdbcmysql/jdbcsqlite3/jdbcpostgresql/jdbc)
                                                         # Default: sqlite3
  -j, [--javascript=JAVASCRIPT]                          # Preconfigure for selected JavaScript library
                                                         # Default: jquery
  -J, [--skip-javascript], [--no-skip-javascript]        # Skip JavaScript files
      [--dev], [--no-dev]                                # Setup the application with Gemfile pointing to your Rails checkout
      [--edge], [--no-edge]                              # Setup the application with Gemfile pointing to Rails repository
  -T, [--skip-test-unit], [--no-skip-test-unit]          # Skip Test::Unit files
      [--rc=RC]                                          # Path to file containing extra configuration options for rails command
      [--no-rc], [--no-no-rc]                            # Skip loading of extra configuration options from .railsrc file

Runtime options:
  -f, [--force]                    # Overwrite files that already exist
  -p, [--pretend], [--no-pretend]  # Run but do not make any changes
  -q, [--quiet], [--no-quiet]      # Suppress status output
  -s, [--skip], [--no-skip]        # Skip files that already exist

Rails options:
  -h, [--help], [--no-help]        # Show this help message and quit
  -v, [--version], [--no-version]  # Show Rails version number and quit

Description:
    The 'rails new' command creates a new Rails application with a default
    directory structure and configuration at the path you specify.

    You can specify extra command-line arguments to be used every time
    'rails new' runs in the .railsrc configuration file in your home directory.

    Note that the arguments specified in the .railsrc file don't affect the
    defaults values shown above in this help message.

Example:
    rails new ~/Code/Ruby/weblog

    This generates a skeletal Rails installation in ~/Code/Ruby/weblog.
    See the README in the newly created application to get going.

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请帮帮我。非常感谢

这意味着命令找不到任何rails应用程序。 请检查

config/application.rb

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或者其他一些文件可能丢失

谢谢。但是我的项目在另一台计算机上工作。我想我的电脑少了一个图书馆。但我不知道。