无法安装 rails 3.2.9：无法构建 gem 原生扩展答案

【问题标题】：Can't install rails 3.2.9: Failed to build gem native extension无法安装 rails 3.2.9：无法构建 gem 原生扩展
【发布时间】：2014-05-11 07:41:41
【问题描述】：

我just cleaned rvm 和 ruby 并重新安装了它。我正在尝试安装 Rails，但出现此错误：

gem install rails -v 3.2.9

Building native extensions.  This could take a while...
ERROR:  Error installing rails:
    ERROR: Failed to build gem native extension.

        /usr/bin/ruby1.9.1 extconf.rb
/usr/lib/ruby/1.9.1/rubygems/custom_require.rb:36:in `require': cannot load such file -- mkmf (LoadError)
    from /usr/lib/ruby/1.9.1/rubygems/custom_require.rb:36:in `require'
    from extconf.rb:1:in `<main>'


Gem files will remain installed in /var/lib/gems/1.9.1/gems/json-1.8.1 for inspection.
Results logged to /var/lib/gems/1.9.1/gems/json-1.8.1/ext/json/ext/generator/gem_make.out

如果我用我的Gemfile 运行bundle install，它有rails 3.2.9 和更多的宝石，我会得到这个错误：

An error occurred while installing json (1.8.1), and Bundler cannot continue.
Make sure that `gem install json -v '1.8.1'` succeeds before bundling.

你猜怎么着。运行建议的命令会给我另一个错误：

Building native extensions.  This could take a while...
ERROR:  Error installing json:
    ERROR: Failed to build gem native extension.

        /usr/bin/ruby1.9.1 extconf.rb
/usr/lib/ruby/1.9.1/rubygems/custom_require.rb:36:in `require': cannot load such file -- mkmf (LoadError)
    from /usr/lib/ruby/1.9.1/rubygems/custom_require.rb:36:in `require'
    from extconf.rb:1:in `<main>'


Gem files will remain installed in /var/lib/gems/1.9.1/gems/json-1.8.1 for inspection.
Results logged to /var/lib/gems/1.9.1/gems/json-1.8.1/ext/json/ext/generator/gem_make.out

【问题讨论】：

你的操作系统是什么？

标签： ruby-on-rails ruby ruby-on-rails-3

【解决方案2】：

一个简单的谷歌搜索指向这个早期的 stackoverflow 问题：

Why do I get an error installing the JSON gem in Ubuntu?

安装 ruby1.9.1-dev 包应该可以解决这个问题：

sudo apt-get install ruby1.9.1-dev

【讨论】：