netoptimizer
commented
5 years ago If the kernel source is in a non-standard place, then you need to specify it in the command line when running make, like:
make kbuilddir=~/git/kernel/net-next/
This should be clear from the Makefile comment.
It is also documented here: https://prototype-kernel.readthedocs.io/en/latest/prototype-kernel/build-process.html
ERROR: Need kernel source code to compile against and specifically tools/lib/bpf
In Opensuse the kernel source is located /usr/src/linux linux is a symlink to another folder linux with the version # after it.
Your make file does NOT find it.