Ruby: require': no such file to load -- mkmf

При установке всякой дополнительной обвязки вокруг Chef на Ruby вываливается ошибка

$ sudo gem install knife-github-cookbooks
Building native extensions.  This could take a while...
ERROR:  Error installing knife-github-cookbooks:
 ERROR: Failed to build gem native extension.

/usr/bin/ruby1.8 extconf.rb
extconf.rb:1:in `require': no such file to load -- mkmf (LoadError)
 from extconf.rb:1


Gem files will remain installed in /var/lib/gems/1.8/gems/json-1.7.7 for inspection.
Results logged to /var/lib/gems/1.8/gems/json-1.7.7/ext/json/ext/generator/gem_make.out

Решение

$ sudo apt-get install ruby1.8-dev

Наслаждаемся ;-)