Thanks for looking into this, Daniel.
On 10/09/2019 02:24, Daniel Kahn Gillmor wrote: > I note here that you're not running the latest kernel -- 4.19.0-5-amd64 > is not 4.19.0-6-amd64. is it possible that you don't have > linux-image-4.19.0-5-amd64 or its headers installed any more, despite > running that kernel? I did, and still do have the headers for the currently running kernel installed: linux-headers-4.19.0-5-amd64/stable,now 4.19.37-5+deb10u2 amd64 [installed,automatic] linux-headers-4.19.0-6-amd64/stable,now 4.19.67-2 amd64 [installed,automatic] However, I rebooted the machine since to boot into 4.19.0-6, re-installed wireguard-dkms and have a successful build this time. I could have tried that earlier but I'm not in a habit of rebooting my machine. Regards, David