The zfs-dkms module fails to build without kernel headers, yet there seem to be no dependency set on that package.
This is the case with all dkms modules, so the dependency belongs on dkms, if anywhere.
I believe it's intentional that it's NOT on the dkms package. There's a Recommends, but not a Depends. IIRC, the rationale was that people might have custom kernels.
-- Richard
