Debian-Server:/home/ben/Desktop# sh VBoxLinuxAdditions-x86.run
Verifying archive integrity... All good.
Uncompressing VirtualBox 3.1.2 Guest Additions for Linux........
VirtualBox Guest Additions installer
Building the VirtualBox Guest Additions kernel modules ...fail!
(Your system does not seem to be set up to build kernel modules.
Look at /var/log/vboxadd-install.log to find out what went wrong)
Installing the Window System drivers
Installing X.Org Server 1.4 modules ...done.
Setting up the Window System to use the Guest Additions ...done.
You may need to restart the hal service and the Window System (or just restart
the guest system) to enable the Guest Additions.
Installing graphics libraries and desktop services components ...done.
Debian-Server:/home/ben/Desktop#