Bug#906903: nvidia-driver: broken(?) dependencies

[Vincent McIntyre]

On Wed, Aug 22, 2018 at 03:57:51PM +0100, Luca Boccassi wrote:
> 
> Because I suspect something on your system is causing some packages to
> be picked from backports and some from stable. That's what's breaking.
> So try and remove any custom configuration you have for apt and then it
> should work.
> 

I broke down and read apt_preferences(5) again and found this:

  If the target release has been specified then APT uses the following
  algorithm to set the priorities of the versions of a package. Assign:
  ...
  priority 990
      to the versions that belong to the target release.
  The highest of those priorities whose description matches the version
  is assigned to the version.

So I think my apt configuration is ok.

I did the experiment (comment out default-release setting)
but it still falls over:

# apt-cache policy nvidia-driver
nvidia-driver:
  Installed: (none)
  Candidate: 384.130-1
  Version table:
     390.77-1~bpo9+1 200
        200 http://debian-archive.atnf.csiro.au:9999/debian stretch-backports/non-free amd64 Packages
     384.130-1 500
        500 http://debian-archive.atnf.csiro.au:9999/debian stretch/non-free amd64 Packages

# apt-get install nvidia-driver
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 nvidia-driver : Depends: nvidia-driver-libs (= 384.130-1) but it is not going to be installed or
                          nvidia-driver-libs-nonglvnd (= 384.130-1) but it is not going to be installed
E: Unable to correct problems, you have held broken packages.



This preferences tweak kind of fixes the issue for me

# cat /etc/apt/preferences.d/backports
Explanation: Low priority to avoid installation unless explicitly required
Package: *
Pin: release a=stretch-backports
Pin-Priority: 200
Explanation: Negative priority; mixing stable & backports not supported
Package: nvidia* libnvidia* libegl* libgl* glx-*
Pin: release a=stretch-backports
Pin-Priority: -1

# apt-cache policy nvidia-driver
nvidia-driver:
  Installed: (none)
  Candidate: 384.130-1
  Version table:
     390.77-1~bpo9+1 -1
        100 http://debian-archive.atnf.csiro.au:9999/debian stretch-backports/non-free amd64 Packages
     384.130-1 990
        990 http://debian-archive.atnf.csiro.au:9999/debian stretch/non-free amd64 Packages

# apt-get install nvidia-driver
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following additional packages will be installed:
  glx-alternative-mesa glx-alternative-nvidia glx-diversions libegl-nvidia0
  libegl1-glvnd-nvidia libgl1-glvnd-nvidia-glx libgl1-nvidia-glvnd-glx
  libglvnd0-nvidia libglx-nvidia0 libglx0-glvnd-nvidia libnvidia-eglcore
  libnvidia-glcore libnvidia-ml1 nvidia-alternative nvidia-driver-bin
  nvidia-driver-libs nvidia-egl-common nvidia-egl-icd nvidia-installer-cleanup
  nvidia-kernel-common nvidia-kernel-dkms nvidia-kernel-support
  nvidia-legacy-check nvidia-modprobe nvidia-support nvidia-vdpau-driver
  update-glx xserver-xorg-video-nvidia
Recommended packages:
  nvidia-settings nvidia-persistenced nvidia-driver-libs-i386 libopengl0
  | libopengl0-glvnd-nvidia libgles-nvidia1 libgles-nvidia2 libnvidia-cfg1
  nvidia-egl-wayland-icd nvidia-vulkan-icd
The following NEW packages will be installed:
  glx-alternative-mesa glx-alternative-nvidia glx-diversions libegl-nvidia0
  libegl1-glvnd-nvidia libgl1-glvnd-nvidia-glx libgl1-nvidia-glvnd-glx
  libglvnd0-nvidia libglx-nvidia0 libglx0-glvnd-nvidia libnvidia-eglcore
  libnvidia-glcore libnvidia-ml1 nvidia-alternative nvidia-driver
  nvidia-driver-bin nvidia-driver-libs nvidia-egl-common nvidia-egl-icd
  nvidia-installer-cleanup nvidia-kernel-common nvidia-kernel-dkms
  nvidia-kernel-support nvidia-legacy-check nvidia-modprobe nvidia-support
  nvidia-vdpau-driver update-glx xserver-xorg-video-nvidia
0 upgraded, 29 newly installed, 0 to remove and 8 not upgraded.
Need to get 29.7 MB of archives.
After this operation, 119 MB of additional disk space will be used.
Do you want to continue? [Y/n] n
Abort.

Thanks for your help with this
Vince