Hello,

It seems that vboxadd service requires a missing file:

config=/var/lib/VBoxGuestAdditions/config
...
start()
{
    begin "Starting the VirtualBox Guest Additions ";
    if test -r $config; then
      . $config
    else
      fail "Configuration file $config not found"
    fi
    test -n "$INSTALL_DIR" -a -n "$INSTALL_VER" ||
      fail "Configuration file $config not complete"

It simply aborts if /var/lib/VBoxGuestAdditions/config is missing or does not
contain INSTALL_DIR/INSTALL_VER. Although, additions seem to still work.

No virtualbox-guest-* packages provides that config file. This config file is
generated by the VBoxAdditions.run when additions are installed from vbox
media.

If I simply comment these tests, it starts nicely. Alternatively, I can create
a stub config file with the required fields.