From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pjotr Prins Subject: Re: updating list of substitutes Date: Sun, 11 Oct 2015 23:27:14 +0200 Message-ID: <20151011212714.GA9401@thebird.nl> References: <20150421064525.GA15795@thebird.nl> <87a8y1q49z.fsf@gnu.org> <20150421084028.GB16564@thebird.nl> <20150422114635.GA24566@thebird.nl> <20151011074654.GA8058@thebird.nl> <87wputz1uj.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]:37625) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZlOBd-0002Lz-8a for guix-devel@gnu.org; Sun, 11 Oct 2015 17:29:46 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZlOBZ-0005QI-S3 for guix-devel@gnu.org; Sun, 11 Oct 2015 17:29:45 -0400 Content-Disposition: inline In-Reply-To: <87wputz1uj.fsf@gnu.org> 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-bounces+gcggd-guix-devel=m.gmane.org@gnu.org To: Ludovic =?iso-8859-1?Q?Court=E8s?= Cc: guix-devel@gnu.org On Sun, Oct 11, 2015 at 08:39:32PM +0200, Ludovic Court=C3=A8s wrote: > No! Slowness is a longstanding issue of hydra.gnu.org, a poor little > VM. I hope we can address it soon! See > . Looking forward to that :) > > It appears to me that if the list does not change it should not be > > downloaded. >=20 > It=E2=80=99s not downloaded =E2=80=9Cevery time.=E2=80=9D >=20 > When building a package FOO, Guix looks for substitutes for FOO and its > prerequisites (those not already available locally.) It maintains in > /var/guix/substitute/cache a cache of those lookups. > Positive caches (for substitutes that are available) expire after 36h; > negative caches (substitutes that are missing) expire after 3h. The weird thing is that most times I install a new package it does a lookup. Only rarely it does not. According to the TTL it should then check every 3hrs at most? Somehow I don't understand why we need to download the substitute list every time I install a new package. Not even Debian does that ;) I would think that the list of (prebuild, right?) substitutes is only updated when some build is triggered. Could be there are builds triggered while I am installing software forcing a new list every time. Is that it? I understand we have a list of prebuilt packages and that the list can change. But maybe I am too simplistic in my assumptions. I'll look into that code tomorrow. Pj.