From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mp2 ([2001:41d0:2:4a6f::]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) by ms11 with LMTPS id QE+wC6+wDV85CAAA0tVLHw (envelope-from ) for ; Tue, 14 Jul 2020 13:18:39 +0000 Received: from aspmx1.migadu.com ([2001:41d0:2:4a6f::]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) by mp2 with LMTPS id YHyPB6+wDV+kEgAAB5/wlQ (envelope-from ) for ; Tue, 14 Jul 2020 13:18:39 +0000 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by aspmx1.migadu.com (Postfix) with ESMTPS id C065F9404CB for ; Tue, 14 Jul 2020 13:18:38 +0000 (UTC) Received: from localhost ([::1]:39860 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jvKpR-0001cD-Hf for larch@yhetil.org; Tue, 14 Jul 2020 09:18:37 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:53380) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jvKpC-0001c2-Qv for guix-devel@gnu.org; Tue, 14 Jul 2020 09:18:23 -0400 Received: from fencepost.gnu.org ([2001:470:142:3::e]:58684) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jvKp5-0006On-1z; Tue, 14 Jul 2020 09:18:15 -0400 Received: from [2a01:e0a:1d:7270:af76:b9b:ca24:c465] (port=37260 helo=ribbon) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1jvKp4-00012P-AT; Tue, 14 Jul 2020 09:18:14 -0400 From: =?utf-8?Q?Ludovic_Court=C3=A8s?= To: Konrad Hinsen Subject: Re: Reproducible Research Hackathon: Friday, July 3rd References: <86fta8cyna.fsf@gmail.com> <875zarr0pk.fsf@gnu.org> X-URL: http://www.fdn.fr/~lcourtes/ X-Revolutionary-Date: 27 Messidor an 228 de la =?utf-8?Q?R=C3=A9volution?= X-PGP-Key-ID: 0x090B11993D9AEBB5 X-PGP-Key: http://www.fdn.fr/~lcourtes/ludovic.asc X-PGP-Fingerprint: 3CE4 6455 8A84 FDC6 9DB4 0CFB 090B 1199 3D9A EBB5 X-OS: x86_64-pc-linux-gnu Date: Tue, 14 Jul 2020 15:18:12 +0200 In-Reply-To: (Konrad Hinsen's message of "Tue, 14 Jul 2020 10:13:59 +0200") Message-ID: <878sfmme0b.fsf@gnu.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-BeenThere: guix-devel@gnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "Development of GNU Guix and the GNU System distribution." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: guix-devel@gnu.org, guix-hpc@gnu.org, simon tournier Errors-To: guix-devel-bounces+larch=yhetil.org@gnu.org Sender: "Guix-devel" X-Scanner: scn0 Authentication-Results: aspmx1.migadu.com; dkim=none; dmarc=none; spf=pass (aspmx1.migadu.com: domain of guix-devel-bounces@gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=guix-devel-bounces@gnu.org X-Spam-Score: -1.01 X-TUID: WKTOllwg3OSG Hi Konrad, Konrad Hinsen skribis: > Indeed. The details are here: > > https://gitlab.inria.fr/guix-hpc/guix-past/-/issues/1 Oooh, thank you! It looks like an =E2=80=9Cinteresting=E2=80=9D bug, one o= f those that can help make the case for precise software environment control. :-) bonfacemunyoki@gmail.com (Bonface M. K.) skribis: > That's strange. To get the right results, you'd have to do a `2L ** 64`. > When I tried `2 ** 63` I got `-9223372036854775808`. There's also an > overflow error. Here's a snippet of what fails from > Python-2.4.6/Lib/test: > > ``` > # If this fails, probably using a strict IEEE-754 conforming libm, an= d x > # is +Inf afterwards. But Python wants overflows detected by default. > try: > x =3D math.exp(1000000000) > except OverflowError: > pass > else: > raise TestFailed("overflowing exp() didn't trigger OverflowError") > ``` > > Maybe there's an overflow somewhere and we'd have to tweak libm? I'm > speculating though. I'd have to investigate this later. Uh, weird! We could check whether building Python with =E2=80=98-fwrapv=E2= =80=99 helps. See also . Ludo=E2=80=99.