How can we be sure that a new kernel has the suitable stuff to compile
kernel modules?
(before launching dnf upgrade, of course....)
By watching the Fedora Forum and this list list. I have an old iMac that lacks an iGPU, so
when a new kernel appears I switch to nouveau so if dnf fails I don't get a black screen.
The rpmfusion howto has a section on switching, which does require a reboot. You can
either edit the kernel command-line in the grub2 editor or edit /etc/default/grub and then
run grub2-mkconfig -o /boot/grub2/grub.cfg.