bug#34902: guix cannot find a module on boot

["Ludovic Courtès" <ludo@gnu.org>]

Hello!

Danny Milosavljevic <dannym@scratchpost.org> skribis:

> Maybe I'm too paranoid but can we have "guix" in the file name "modules.name"
> somewhere?  Otherwise I see it coming that upstream uses modules.name for an
> incompatible purpose and then we'd be with a guix interface that's broken
> and/or break their interface.
>
> (So much complexity for something so silly.  Honestly, I feel like E-mailing
> the upstream author and telling him what I think.  WTF :P)
>
> Should we warn when we use the fallback?  I like the defensive programming
> but I feel we shouldn't have it *silently* fall back when the database is
> broken/missing.
>
> Otherwise LGTM!

So I went ahead and pushed these patches, derived from our beautiful
patch set at <https://issues.guix.gnu.org/issue/30604>:

  c85ccf60bf linux-modules: Define and use a module name database.
  e1a9a7f275 linux-modules: Add 'load-linux-modules-from-directory'.
  2a693b69ca linux-modules: Add "modules.devname" writer.
  4f8b9d1a6f linux-modules: Add "modules.alias" writer.

The actual fix for the hyphen/underscore mismatch that Julien reported
is commit c85ccf60bf.  The “modules.devname” and “modules.alias” are
actually unused so far but (1) it was easier to preserve them, and (2)
that’ll give us an incentive to finish
<https://issues.guix.gnu.org/issue/30604>.  :-)

I added an explicit comment that “modules.name” uses a Guix-specific
format.  We can always rename it if the kernel folks decide to acquire
that file name.

Julien, could you please confirm that your initial issue is fixed?

Thanks,
Ludo’.