Hi,

Here's a serie to add target support to guix system command. Most of the
patches were reviewed in v1 by Marius and Ludo, but this serie adds some more
patches to complete target support.

Using the dummy system in attachment, I'm able to generate a cross-built guix
system with this command:

--8<---------------cut here---------------start------------->8---
 ./pre-inst-env guix system disk-image gnu/system/examples/mini.scm --target=aarch64-linux-gnu
--8<---------------cut here---------------end--------------->8---

Some of the patches in this serie are from a friend Pierre-Moana who
helped me much here.

Next step is to find an aarch64 board and boot it with a cross-built
guix system!

I pushed those patches to wip-cross-system branch of savannah.

Thanks,

Mathieu