v4l2loopback-dkms 0.8.0-4ubuntu1: v4l2loopback kernel module failed to build [error: ‘struct video_device’ has no member named ‘debug’]

[Vindicator]

"Upgrading" to mainline-crack 4.0

$ sudo dpkg -i linux*4.0.0-040000-generic_4.0.0-040000.201504121935+testSigned_amd64*.deb

This caused the errors:
*****
run-parts: executing /etc/kernel/postinst.d/dkms 4.0.0-040000-generic /boot/vmlinuz-4.0.0-040000-generic
Error! Bad return status for module build on kernel: 4.0.0-040000-generic (x86_64)
Consult /var/lib/dkms/v4l2loopback/0.8.0/build/make.log for more information.
Error! Bad return status for module build on kernel: 4.0.0-040000-generic (x86_64)
Consult /var/lib/dkms/webcamstudio/0.73/build/make.log for more information.
*****

make.log
*****
DKMS make.log for v4l2loopback-0.8.0 for kernel 4.0.0-040000-generic (x86_64)
Tue Jun 16 15:32:00 CDT 2015
Building v4l2-loopback driver...
make -C /lib/modules/4.0.0-040000-generic/build M=/var/lib/dkms/v4l2loopback/0.8.0/build modules
make[1]: Entering directory '/usr/src/linux-headers-4.0.0-040000-generic'
  CC [M] /var/lib/dkms/v4l2loopback/0.8.0/build/v4l2loopback.o
/var/lib/dkms/v4l2loopback/0.8.0/build/v4l2loopback.c: In function ‘init_vdev’:
/var/lib/dkms/v4l2loopback/0.8.0/build/v4l2loopback.c:2006:7: error: ‘struct video_device’ has no member named ‘debug’
   vdev->debug = V4L2_DEBUG_IOCTL | V4L2_DEBUG_IOCTL_ARG;
       ^
/var/lib/dkms/v4l2loopback/0.8.0/build/v4l2loopback.c:2006:17: error: ‘V4L2_DEBUG_IOCTL’ undeclared (first use in this function)
   vdev->debug = V4L2_DEBUG_IOCTL | V4L2_DEBUG_IOCTL_ARG;
                 ^
/var/lib/dkms/v4l2loopback/0.8.0/build/v4l2loopback.c:2006:17: note: each undeclared identifier is reported only once for each function it appears in
/var/lib/dkms/v4l2loopback/0.8.0/build/v4l2loopback.c:2006:36: error: ‘V4L2_DEBUG_IOCTL_ARG’ undeclared (first use in this function)
   vdev->debug = V4L2_DEBUG_IOCTL | V4L2_DEBUG_IOCTL_ARG;
                                    ^
scripts/Makefile.build:264: recipe for target '/var/lib/dkms/v4l2loopback/0.8.0/build/v4l2loopback.o' failed
make[2]: *** [/var/lib/dkms/v4l2loopback/0.8.0/build/v4l2loopback.o] Error 1
Makefile:1390: recipe for target '_module_/var/lib/dkms/v4l2loopback/0.8.0/build' failed
make[1]: *** [_module_/var/lib/dkms/v4l2loopback/0.8.0/build] Error 2
make[1]: Leaving directory '/usr/src/linux-headers-4.0.0-040000-generic'
Makefile:42: recipe for target 'v4l2loopback.ko' failed
make: *** [v4l2loopback.ko] Error 2
*****

I'll be removing both packages, reinstalling the kernel before even considering rebooting.

ProblemType: Package
DistroRelease: Ubuntu 15.04
Package: v4l2loopback-dkms 0.8.0-4ubuntu1
ProcVersionSignature: Ubuntu 3.19.0-21.21-generic 3.19.8
Uname: Linux 3.19.0-21-generic x86_64
ApportVersion: 2.17.2-0ubuntu1.1
Architecture: amd64
DKMSKernelVersion: 4.0.0-040000-generic
Date: Tue Jun 16 15:32:04 2015
DuplicateSignature: dkms:v4l2loopback-dkms:0.8.0-4ubuntu1:/var/lib/dkms/v4l2loopback/0.8.0/build/v4l2loopback.c:2006:7: error: ‘struct video_device’ has no member named ‘debug’
InstallationDate: Installed on 2015-06-04 (12 days ago)
InstallationMedia: Ubuntu 15.04 "Vivid Vervet" - Release amd64 (20150422)
PackageArchitecture: all
PackageVersion: 0.8.0-4ubuntu1
RelatedPackageVersions:
 dpkg 1.17.25ubuntu1
 apt 1.0.9.7ubuntu4.1
SourcePackage: v4l2loopback
Title: v4l2loopback-dkms 0.8.0-4ubuntu1: v4l2loopback kernel module failed to build
UpgradeStatus: No upgrade log present (probably fresh install)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.