For Fedora 34 users (still in development, nearing beta).
There is a known problem currently occurring with any OOT kmod (Out Of Tree kernel modules), such as nvidia, virtualbox, v4l2loopback that make it impossible to build. It’s usually best to use rpmfusion for theses components, but any OOT kmod are concerned.
The current workaround if you experience build failure for theses is to downgrade the gcc version using:
dnf downgrade gcc*
Then “akmods --force” should works.
The problem is currently been discussed upstream (gcc/kernel) and is related to gcc plugins been too strict about it’s compatibility. It enforces the exact gcc version to build the kmod the same as the one used to buidld the kernel. This problem should disappear once Fedora is out of beta (so the latest gcc release is the one used to build the kernel and any end-user kmod).