This comes up quite often, long story short it can't require kernel-devel because it's also designed to work with custom or vanilla kernels, so it has a special require, unfortunately it's currently pulling in kernel-debug-devel instead, which is a bug on the Fedora side but they don't seem particularly interested in fixing it. There's some proposed changes to fix that both for kernel-devel and dnf/yum but I just got home after a 10 hour drive from vacation so there's not a fix coming until I have a chance to dig into it a bit more. There's a yum->dnf compat package you can install that will symbolically link /usr/bin/yum to /usr/bin/dnf but the name escapes me at the moment.

Thanks,
RIchard