Rails安装在Ubuntu上失败，“无法加载这样的文件 – mkmf”
在Ubuntu 11上安装Rails的时候遇到这个问题：
root@salah:/home/salah/rubygems-1.8.15# sudo gem install mysql Fetching: mysql-2.8.1.gem (100%) Building native extensions. This could take a while... ERROR: Error installing mysql: ERROR: Failed to build gem native extension. /usr/bin/ruby1.9.1 extconf.rb /usr/local/lib/site_ruby/1.9.1/rubygems/custom_require.rb:36:in `require': cannot load such file -- mkmf (LoadError) from /usr/local/lib/site_ruby/1.9.1/rubygems/custom_require.rb:36:in `require' from extconf.rb:10:in `<main>' Gem files will remain installed in /usr/lib/ruby/gems/1.9.1/gems/mysql-2.8.1 for inspection. Results logged to /usr/lib/ruby/gems/1.9.1/gems/mysql-2.8.1/ext/mysql_api/gem_make.out 如果我没有弄错的话，mkmf是ruby-dev包的一部分。 尝试：
sudo aptitude install ruby1.9.1-dev
当然，你可能会更好通过RVM安装ruby:)
对于Ubuntu 13.04，这是对我有用：
sudo apt-get install ruby-dev
尝试rvm all do gem install nokogiri
