This issue still occurs as of 5.8.0-1. The work around to make it compile is to symlink the missing folder from kernel source:
`sudo ln -s /usr/src/linux-headers-5.8.0-1-common/include/linux /lib/modules/5.8.0-1-amd64/build/include/linux`
- Bug#969477: zfs-dkms fails to compile with 5.7.... Jordan Mendler
- Bug#969477: Acknowledgement (zfs-dkms fail... Jordan Mendler
- Bug#969477: Jordan Mendler
- Bug#969477: zfs-dkms fails to compile with... Mo Zhou
- Processed: Re: zfs-dkms fails to compile w... Debian Bug Tracking System
