无法安装Jeky

Question

我得到错误（Ubuntu 14.04）：

sudo gem install 

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

    /usr/bin/ruby2.1 extconf.rb
mkmf.rb can't find header files for ruby at /usr/lib/ruby/include/ruby.h

extconf failed, exit code 1

Gem files will remain installed in /var/lib/gems/2.1.0/gems/ffi-1.9.14 for inspection.
Results logged to /var/lib/gems/2.1.0/extensions/x86_64-linux/2.1.0/ffi-1.9.14/gem_make.out

像安装ruby dev这样的常见解决方案不起作用。你知道吗

求你了救命。谢谢. 你知道吗