From: Justin Forbes on
gitlab.com
https://gitlab.com/cki-project/kernel-ark/-/merge_requests/1035#note_5783...
Right, so the Makefile generates vmlinux.h if the value is null, and
copies it over if the value is set to something. We could probably
simplify this even more. I assumed there was a flag passed in cki to
rpmbuild for --only-tools or something, but I don't see it. If we had
such a flag, we could key off of that and set VMLINUX_H to the path for
this specific kernel in kernel-devel. If we are building without that
flag, it would be null and then generate it's own.