autobuilding src:nvidia-* [non-free]

[Russ Allbery]

Philipp Kern <pkern at debian.org> writes:

> I'm a bit confused why that is. If I'm installing a
> nvidia-graphics-driver package that does all the magic using dkms at
> install time, how is that more sophisticated than providing pre-built
> module packages, especially in the light that it's the only one left
> doing it that way?

The main problem with the DKMS approach is that you have to have a version
of the kernel headers installed that matches the version of the kernel
that you have.  If you don't, you just don't get the module, and then
stuff doesn't work.  People seem to really struggle with this when they
don't understand what's going on under the hood, and our dependency system
is not powerful enough to clearly express this dependency.

With the prebuilt modules, you can just install the meta tracking package
for the nvidia modules and from the perspective of the user it just works,
since the packaging takes care of keeping the dependencies in sync with
the kernel module versions.  It's more fragile from a Debian perspective,
but within a stable release it means the user doesn't have to notice that
they need the header package installed.  (Admittedly, with the DKMS
approach, you can just install the header tracking package and once you
have that installed, similarly everything will just work.  The confusion
seems to come from people not realizing that they need to also install the
header tracking package; they find the NVIDIA DKMS package and then don't
realize that's not enough.)

It's a relatively minor benefit, I'll grant.  If I were doing all the
NVIDIA stuff by myself, I wouldn't bother, but I can see some benefit as
long as Andreas wants to keep doing the work.  I think what we're
currently doing doesn't put a lot of work on anyone else, other than some
work for ftp-master approving the new packages after an ABI update and the
release team approving freeze exceptions for the new packages after an ABI
update.  I'm not sure if that work is a strong argument against doing
this.

I noticed that dkms now Recommends the tracking kernel header package, so
maybe that makes this somewhat more obsolete.  That means that the average
user should, through the dependency tree, get the header package installed
when they install nvidia-modules-dkms, which in turn they should get via
Recommends from nvidia-graphics-modules.

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