Vagrantでエラーに当たってちょっと調べ物したので記録しとく。 起きたこと 久しぶりに、Vagrantを使って Ubuntu 15の環境を作ろうとしたところ、 chef_zero provisionerで以下の様なエラーが出た Failed to mount folders in Linux guest. This is usually because the "vboxsf" file system is not available. Please verify that the guest additions are properly installed in the guest and can work properly. The command attempted was: mount -t vboxsf -o uid=`id -u ubuntu`,gid=`getent gr