Re: Offloading to a VM

[ludo@gnu.org (Ludovic Courtès)]

David Craven <david@craven.ch> skribis:

>> --8<---------------cut here---------------start------------->8---
>> $ qemu-arm $(guix build coreutils -s armhf-linux |grep -v debug)/bin/uname -a
>> Linux pluto 4.7.0-gnu #1 SMP 1 armv7l GNU/Linux
>> $ uname -a
>> Linux pluto 4.7.0-gnu #1 SMP 1 x86_64 GNU/Linux
>> --8<---------------cut here---------------end--------------->8---
>
> If I understand correctly this only works when there is a substitute
> already. If it's a new package for example that would fail with "not
> an armhf system" right?

The “build hook” is the mechanism by which the daemon asks an external
program whether it can build a derivation for some system.

Our (guix scripts offload) is such a program; it replies positively if
there’s a machine that matches the target system.

What I was suggesting is to have another build hook that would reply
positively as long as the target system can be emulated by QEMU.

Does that makes sense?

Thanks,
Ludo’.