Irritating as it can be when something that should work does not, it is even more irritating when the error message is misleading. For example, today I came across an error when installing Guest Additions for Virtualbox in a Linux VM. The Guest additions failed and gave the possible cause as the lack of generic-headers. However, it is not the headers, which were installed, but DKMS. To solve this, install ‘build-essentials’ package.