Comment 6 for bug 1777646

The proposed package fails to install but does manage to build.

This is the install log:
i915
leith@leith-xps:~$ sudo apt-get install bcmwl-kernel-source
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages were automatically installed and are no longer required:
  libllvm5.0 libllvm5.0:i386 linux-headers-4.13.0-43
  linux-headers-4.13.0-43-generic linux-image-4.13.0-43-generic
  linux-image-extra-4.13.0-43-generic
Use 'sudo apt autoremove' to remove them.
The following NEW packages will be installed
  bcmwl-kernel-source
0 to upgrade, 1 to newly install, 0 to remove and 24 not to upgrade.
Need to get 1,547 kB of archives.
After this operation, 8,067 kB of additional disk space will be used.
Get:1 http://archive.ubuntu.com/ubuntu xenial-proposed/restricted amd64 bcmwl-kernel-source amd64 6.30.223.271+bdcom-0ubuntu1~1.3 [1,547 kB]
Fetched 1,547 kB in 2s (536 kB/s)
Selecting previously unselected package bcmwl-kernel-source.
(Reading database ... 441614 files and directories currently installed.)
Preparing to unpack .../bcmwl-kernel-source_6.30.223.271+bdcom-0ubuntu1~1.3_amd64.deb ...
Unpacking bcmwl-kernel-source (6.30.223.271+bdcom-0ubuntu1~1.3) ...
Setting up bcmwl-kernel-source (6.30.223.271+bdcom-0ubuntu1~1.3) ...
Loading new bcmwl-6.30.223.271+bdcom DKMS files...
First Installation: checking all kernels...
Building only for 4.15.0-24-generic
Building for architecture x86_64
Building initial module for 4.15.0-24-generic
Done.

wl:
Running module version sanity check.
 - Original module
   - No original module exists within this kernel
 - Installation
   - Installing to /lib/modules/4.15.0-24-generic/updates/dkms/

depmod....

DKMS: install completed.
modprobe: ERROR: could not insert 'wl': Required key not available
update-initramfs: deferring update (trigger activated)
Processing triggers for shim-signed (1.33.1~16.04.1+13-0ubuntu2) ...
Processing triggers for initramfs-tools (0.122ubuntu8.11) ...
update-initramfs: Generating /boot/initrd.img-4.15.0-24-generic
W: Possible missing firmware /lib/firmware/i915/kbl_guc_ver9_14.bin for module i915
W: Possible missing firmware /lib/firmware/i915/bxt_guc_ver8_7.bin for module i915
leith@leith-xps:~$