Re: Starting 'core-updates'?

[Ludovic Courtès]

Hi!

Christopher Baines <address@hidden> skribis:

> Something I'd be interested in learning more about is
> cross-compilation. The Guix Data Service computes some derivations for
> cross-compilation (see the table on the right of [1] for example), but
> I'm not sure if these are the right one, and because there aren't any
> automated builds for these derivations as far as I'm aware, it's
> difficult to know if they can actually be built.
>
> 1: http://data.guix.gnu.org/revision/ac841750a52e44d68d7f1b02e9507421f3e3824f
>
> I'm coming to the Guix Days, so maybe it's something that can be talked
> about then.

Definitely!

The short story though is that there’s confusion between “system types”
(like “x86-64_linux”) and GNU triplets (like “x86_64-linux-gnu”,
“arm-linux-gnueabihf”, etc.).

The former is used by the daemon as an “input”, to distinguish
derivations that target different CPUs or different OS kernels.  It’s
the option you pass to ‘guix build -s’.

The latter is used by the GNU toolchain to identify a target system:
CPU, kernel, userland, and optionally hardware vendor.  It’s what you
pass to ‘guix build --target’.

(gnu ci) contains the list of cross-compilation targets (triplets) that
we intend to support.  I believe these are those you should be
targeting.  Also, we only even build cross toolchain from “x86_64-linux”
because in practice that’s the only well-tested (and relevant) platform
for that.

Ludo’.