状況 rails new で新規プロジェクトを作成 Gemfile に capybara と capybara-webkit を追加 bundle install を実行 次のエラーが発生 [vagrant@vagrant-centos65 foo]$ bundle Fetching gem metadata from https://rubygems.org/.......... Resolving dependencies... # --- 省略 --- Using capybara 2.4.4 Gem::Ext::BuildError: ERROR: Failed to build gem native extension. /home/vagrant/.rbenv/versions/2.1.3/bin/ruby extconf.rb Command 'qmake -spec lin