Bug#590221: Package: nvidia-glx-legacy-173xx

[Russ Allbery]

Steven Altermatt <stevealcnm at gmail.com> writes:

>> nvidia-kernel-dkms

>> Recommends kernel headers -- so you hopefully have the headers for
>> your running kernel installed and the module can be built automatically

> Only if one wants this done automatically, shouldn't be forced upon the
> user. Which happened because the legacy changelog did not have the
> necessary info in it so the user could decide whether to use dkms or
> not.

So, let me explain what happened and why this all worked the way that it
did to provide a bit of background.  This will hopefully also explain why
we thought there was enough information in the legacy changelogs.  This
was an unexpected side effect.

Historically, the primary method of getting a kernel module was to install
the pre-built kernel module maintained by the NVIDIA packagers.  This was
the case for a lot of out-of-tree kernel modules.  The problem with this
approach is that it's a huge headache from the Debian archive maintenance
perspective and requires tons of coordination.  Each time the kernel ABI
changes, every kernel module of this type must be uploaded again, and all
those new packages will have new names and will have to go through NEW
processing.

Because of that, all out-of-tree kernel modules in Debian are generally
converging on DKMS.  The huge advantage of DKMS for the average user is
that if they have the kernel metapackage and the headers metapackage
installed, they can then just merrily upgrade their system without giving
out-of-tree modules a second thought and everything just works.

It does, indeed, not work well if you have a custom-built kernel, but this
is an unusual case for Debian users.

One of the changes in all of the latest uploads of NVIDIA packages was
therefore to add DKMS support and recommend it by default.  This is of
particular interest for the legacy packages, since the legacy packages
have no pre-built kernel modules in Debian.  That's what:

    - add dkms support (closes: #547535)

in the changelog was about.  In retrospect, it probably should have also
said "and recommend it as the default."

Now, for a user such as yourself who is happy with the -source package and
isn't interested in DKMS, the chain of Recommends that Andreas pointed out
earlier end up causing you problems, since they pull in nvidia-glx before
you have had a chance to build the new kernel module and then, from there,
pull in DKMS to try to satisfy the dependency on a kernel module.

I think the solution for your particular problem would be to downgrade the
Recommends of nvidia-glx from nvidia-kernel-source to a Suggests.  I'm not
sure if that would cause any other problems.  At first glance, my guess is
that anyone installing nvidia-kernel-source probably knows enough about
what they're doing that the extra weight of Recommends isn't necessary for
them, so I'm inclined to say that's a good change.  But I'd also like to
see what Andreas thinks.

-- 
Russ Allbery (rra at debian.org)               <http://www.eyrie.org/~eagle/>