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 ;-)