The error means that vboxdrv/vboxadd can't find your kernel sources.

The script expects that /lib/modules/$(uname -r)/build folder points to /usr/src/kernels/$(uname -r) which should have the Makefile where it can execute kernelrelease task, so it can compare against your current installed kernel version (uname -r).

So if this command fails:

make -C /usr/src/kernels/$(uname -r)/build kernelrelease

you should install the Linux headers by:

sudo apt-get install linux-headers-$(uname -r)

For further details, please check this post.

The error means that vboxdrv/vboxadd can't find your kernel sources.

The script expects that /lib/modules/$(uname -r)/build folder points to /usr/src/kernels/$(uname -r) which should have the Makefile where it can execute kernelrelease task, so it can compare against your current installed kernel version (uname -r).

So if this command fails:

make -C /usr/src/kernels/$(uname -r)/build kernelrelease

you should install the Linux headers by:

sudo apt-get install linux-headers-$(uname -r)

For further details, please check this post.