无法构建gem native扩展（mkmf（LoadError）） - Ubuntu 12.04

Question

嘿我正在尝试在新的ubuntu机器上安装rails。我安装了ruby和rvm但是我收到了“未能构建gem native扩展”的错误。这是什么意思？

$ sudo gem install rails -v 3.2.9

（没有sudo说我没有权限）

然后它会输出很多'抓取'命令并最终输出错误：

    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-1.8.0 for inspection.
    Results logged to /var/lib/gems/1.9.1/gems/json-1.8.0/ext/json/ext/generator/gem_make.out

当我输入

$rails server

它表示当前未安装rails

Answer 1

可能重复：

Unable to install gem - Failed to build gem native extension - cannot load such file -- mkmf (LoadError)

根据您的ruby版本，运行：

sudo apt-get install ruby1.9.1-dev

Answer 2

如果您使用的是RVM，则不应使用“sudo”。使用sudo调用libs等rvm路径。试试一下公寓：

gem install rails -v3.2.9

看看是否有帮助。