> Anyway, a second problem appears when it tries to find `stubs32.h`,
> which is supposed to be part of multilib... so it should be part of
> avr-libc in this case but it isn't even installed (I searched for it
> in my Guix profile with no success, but I find `stubs.h`).
>
> Now I need to find why isn't it installed and make it work.
>
> Any idea about how to make `stubs32.h` to be installed?

I did notice your bug report earlier, but didn't reply because I don't
know much about this. :-( I was hoping somebody who knows more would
reply. Anyway, I'll try to do some research on this problem and reply
soon. We'll continue the conversation at the bug report.