Ruby 脚本找不到所需的 gem

Question

我正在尝试运行过去运行良好的 Ruby 脚本。我需要使用 Mechanize gem，所以在脚本的顶部，它显示require 'mechanize'。但是，当我现在尝试运行脚本时，终端输出显示为：

/Users/codebiker/.rvm/rubies/ruby-2.1.0/lib/ruby/site_ruby/2.1.0/rubygems/core_ext/kernel_require.rb:55:in `require': cannot load such file -- mechanize (LoadError)
from /Users/codebiker/.rvm/rubies/ruby-2.1.0/lib/ruby/site_ruby/2.1.0/rubygems/core_ext/kernel_require.rb:55:in `require'
from myscript.rb:2:in `<main>'

当我按照这里的建议运行 gem env 时，我得到：

RubyGems Environment:
  - RUBYGEMS VERSION: 2.2.1
  - RUBY VERSION: 2.1.0 (2013-12-25 patchlevel 0) [x86_64-darwin13.0]
  - INSTALLATION DIRECTORY: /Users/codebiker/.rvm/gems/ruby-2.1.0
  - RUBY EXECUTABLE: /Users/codebiker/.rvm/rubies/ruby-2.1.0/bin/ruby
  - EXECUTABLE DIRECTORY: /Users/codebiker/.rvm/gems/ruby-2.1.0/bin
  - SPEC CACHE DIRECTORY: /Users/codebiker/.gem/specs
  - RUBYGEMS PLATFORMS:
    - ruby
    - x86_64-darwin-13
  - GEM PATHS:
     - /Users/codebiker/.rvm/gems/ruby-2.1.0
     - /Users/codebiker/.rvm/gems/ruby-2.1.0@global
  - GEM CONFIGURATION:
     - :update_sources => true
     - :verbose => true
     - :backtrace => false
     - :bulk_threshold => 1000
     - :benchmark => false
     - :sources => ["http://rubygems.org/", "http://gemcutter.org"]
     - "install" => "--no-rdoc --no-ri"
     - "update" => "--no-rdoc --no-ri"
  - REMOTE SOURCES:
     - http://rubygems.org/
     - http://gemcutter.org
  - SHELL PATH:
     - /Users/codebiker/.rvm/gems/ruby-2.1.0/bin
     - /Users/codebiker/.rvm/gems/ruby-2.1.0@global/bin
     - /Users/codebiker/.rvm/rubies/ruby-2.1.0/bin
     - /usr/local/bin
     - /usr/bin
     - /bin
     - /usr/sbin
     - /sbin
     - /usr/local/bin
     - /opt/X11/bin
     - /usr/texbin
     - /Users/codebiker/.rvm/bin

当我运行rvm get head 时，我得到：

Upgrading the RVM installation in /Users/codebiker/.rvm/
RVM PATH line found in /Users/codebiker/.bashrc /Users/codebiker/.zshrc.
RVM sourcing line found in /Users/codebiker/.bash_profile /Users/codebiker/.zprofile.
Upgrade of RVM in /Users/codebiker/.rvm/ is complete.

当我运行which ruby 时，我得到：

/Users/codebiker/.rvm/rubies/ruby-2.1.0/bin/ruby

ruby -v 给了我：

ruby 2.1.0p0 (2013-12-25 revision 44422) [x86_64-darwin13.0]

任何建议、想法或提示将不胜感激！我不知道这里有什么问题。

Answer 1

必须先安装 Gem，然后才能在脚本中 require 它们。安装gem；首先打开一个终端窗口，然后输入：

gem install GEM-NAME 或者在你的情况下：gem install mechanize

Answer 2

如果您使用bundler，请添加到您的gemfile 链接到mechanize gem：

gem 'mechanize'

然后为您的rails 或其他项目文件夹发出捆绑安装：

$ bundle install

确保安装包后mechanize gem 出现在gemfile.lock 中。

那么即使你不使用 bundler，也要确保 bundle 找到了 gem：

$ bundle show mechanize
/path/to/mechanize/gem

如果您的应用不是 rails 应用，只需运行您的应用：

$ bundle exec ./your_app