Comment 6 for bug 1437100

No need to install the -headers .deb package. Only the linux-image package for your arch. The 4.0-rc7 kernel is now out, so we might as well test that one.

It can be downloaded from:
http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.0-rc7-vivid/

The specific .deb file name is: linux-image-4.0.0-040000rc7-generic_4.0.0-040000rc7.201504061936_amd64.deb