Building Guile with ‘-j1’?

[Ludovic Courtès]

Hi!

As the saying goes, “the cobbler’s children go barefoot”.  Guile/Guix
are no exception since Guile builds are non-reproducible, despite work
done a few years ago:

  https://issues.guix.gnu.org/20272

Until it’s fixed in Guile proper, what do you think of building Guile
2.0/2.2/3.0 with #:parallel-build? #f ?  We could do that in
‘core-updates’ now.

That would work around the problem for Guile itself.  It would increase
build times, but probably not that much since the most expensive part
(compiling the first few files) is sequential anyway.  IIRC this is what
Vagrant did for the Debian packages.

We could also disable parallel builds in ‘guile-build-system’.  It’s
only used for small packages so the extra build time is probably OK.

Thoughts?

Ludo’.