我正在尝试在 ubuntu 12.04 上安装 rails 但我遇到了一些问题
我试过
sudo gem install rails --pre
并得到
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
extconf.rb:13:in `require': cannot load such file -- mkmf (LoadError)
from extconf.rb:13:in `<main>'
Gem files will remain installed in /usr/lib/ruby/gems/1.9.1/gems/atomic-1.1.10 for inspection.
Results logged to /usr/lib/ruby/gems/1.9.1/gems/atomic-1.1.10/ext/gem_make.out