bug#66866: aarch64 system cross compilation + pinebook pro image broken?

[Mathieu Othacehe <othacehe@gnu.org>]

Hey,

> ./pre-inst-env guix system build --target=aarch64-linux-gnu gnu/system/images/pine64.scm
>
>
> which cause an issue in gawk-mesboot:
>
> checking host system type... Invalid configuration `aarch64-linux-gnu': machine `aarch64' not recognized
> configure: error: /gnu/store/rb75igdc6daly1mz2ivz7rs8hd85imdz-gash-boot-0.3.0/bin/bash ./config.sub aarch64-linux-gnu failed
>
> Janneke, do you know what could have caused this regression?

This probably has nothing to do with the bootstrap packages. I noticed
that the CI succeeds in building the pine64 image:
https://ci.guix.gnu.org/build/3265001/details.

The difference is that the CI is building without grafting. Disabling
grafting locally, seems to do the trick as well:

--8<---------------cut here---------------start------------->8---
./pre-inst-env guix system image gnu/system/images/pine64.scm  --no-grafts
--8<---------------cut here---------------end--------------->8---

The issue seems to be that grafting ends-up dragging the bootstrap
packages into the closure when cross-compiling which is quite scary.

Mathieu