From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Craven Subject: Re: Offloading to a VM Date: Sat, 3 Sep 2016 16:27:52 +0200 Message-ID: References: <87bn0pp58b.fsf@gnu.org> <877fb12cf7.fsf_-_@gnu.org> <87r3974txx.fsf@gnu.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Return-path: Received: from eggs.gnu.org ([2001:4830:134:3::10]:37031) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bgBvQ-0002mr-FT for guix-devel@gnu.org; Sat, 03 Sep 2016 10:28:05 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bgBvJ-0002l0-19 for guix-devel@gnu.org; Sat, 03 Sep 2016 10:28:03 -0400 Received: from mail-yw0-x22a.google.com ([2607:f8b0:4002:c05::22a]:33727) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bgBvH-0002kK-QY for guix-devel@gnu.org; Sat, 03 Sep 2016 10:27:56 -0400 Received: by mail-yw0-x22a.google.com with SMTP id l8so17794757ywb.0 for ; Sat, 03 Sep 2016 07:27:53 -0700 (PDT) In-Reply-To: List-Id: "Development of GNU Guix and the GNU System distribution." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: guix-devel-bounces+gcggd-guix-devel=m.gmane.org@gnu.org Sender: "Guix-devel" To: =?UTF-8?Q?Ludovic_Court=C3=A8s?= Cc: guix-devel > The =E2=80=9Cbuild hook=E2=80=9D is the mechanism by which the daemon ask= s 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=E2=80=99s 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. So I thought about this some more. guix offload uses guix build to build a derivation which again uses a different nix-daemon to build it. I'm not sure that guix offload can help us here. If it is possible to build a derivation using only qemu-arm instead of qemu-system-arm - which I'm still not convinced - I think it's the nix-daemon that would have to support this. In build.cc it sets up a chroot and then executes the builder. I think it's that builder that needs to be run with qemu-arm. But I don't think it's going to be as easy as that =3D) Does this make sense?