Subject: Re: [bug#41350] [PATCH v2 3/3] system: vm: Build vm-image using native qemu, for the Hurd.

From: Mathieu Othacehe <[email-masked]>
Date: Fri, 22 May 2020 21:24:42 +0200

Hey Ludo!

>   1. When cross-compiling, can the ‘qemu-image’ procedure to its job by
>      running exclusively native software (in particular using a native
>      QEMU, native kernel, etc.)?

I think the answer is yes, but I raised a concern about being able to
run grub-install from an ARM system to build a cross-compiled x86-64
system (for instance).

For now, running this command shows:

--8<---------------cut here---------------start------------->8---
ls $(guix build --system=aarch64-linux grub)/lib/grub/
arm64-efi
--8<---------------cut here---------------end--------------->8---

So, the native aarch64-linux is only able to install itself on the same
system. I think can be fixed though (same as for grub-hybrid package).

> As for (2), I’d say that when cross-compiling, it should just run native
> software but simply preserve references to cross-compiled software,
> which is what janneke’s patch does.

Yes, I agree.

However, I think I found a way to install Grub, without root
permissions, from the host system (see:
https://lists.gnu.org/archive/html/guix-patches/2020-05/msg00988.html).

This should allow to deprecate the whole (gnu system vm) module.

Thanks for having a look :)

Mathieu