From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mp2 ([2001:41d0:8:6d80::]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) by ms0.migadu.com with LMTPS id kID4Ckf5emACdgAAgWs5BA (envelope-from ) for ; Sat, 17 Apr 2021 17:05:43 +0200 Received: from aspmx1.migadu.com ([2001:41d0:8:6d80::]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) by mp2 with LMTPS id aL9ZBkf5emD8FwAAB5/wlQ (envelope-from ) for ; Sat, 17 Apr 2021 15:05:43 +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 D090116119 for ; Sat, 17 Apr 2021 17:05:42 +0200 (CEST) Received: from localhost ([::1]:33432 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lXmVx-0006BN-Ic for larch@yhetil.org; Sat, 17 Apr 2021 11:05:41 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:44588) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lXmVo-0006B2-O9 for guix-devel@gnu.org; Sat, 17 Apr 2021 11:05:32 -0400 Received: from fencepost.gnu.org ([2001:470:142:3::e]:34781) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lXmVl-00027G-A0; Sat, 17 Apr 2021 11:05:29 -0400 Received: from [2a01:e0a:1d:7270:af76:b9b:ca24:c465] (port=41556 helo=ribbon) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1lXmVi-0000zC-T9; Sat, 17 Apr 2021 11:05:27 -0400 From: =?utf-8?Q?Ludovic_Court=C3=A8s?= To: ilmu Subject: Re: Deep vs Shallow trace: Removing the tradeoff? References: <01A29E7C-0E60-4518-A775-92B6F6A8B816@lepiller.eu> <20210330202030.GA2811@LionPure> X-URL: http://www.fdn.fr/~lcourtes/ X-Revolutionary-Date: 28 Germinal an 229 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: Sat, 17 Apr 2021 17:05:24 +0200 In-Reply-To: (ilmu@rishi.is's message of "Fri, 02 Apr 2021 15:45:18 +0000") Message-ID: <87zgxxt0i3.fsf@gnu.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.2 (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" Errors-To: guix-devel-bounces+larch=yhetil.org@gnu.org Sender: "Guix-devel" X-Migadu-Flow: FLOW_IN ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=yhetil.org; s=key1; t=1618671942; h=from:from:sender:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:list-id:list-help: list-unsubscribe:list-subscribe:list-post; bh=gTZIBvD3UAwcuihFFAUeDle1jOWfdaC86IOophAWfIc=; b=LcHeEq0CEXoFPpnbEqNbm2gA9rjdrH8UZiSPFQDzuo/ih/KvRIonSO8x+bjs4ioZ9xxXXI 09TQrfGrBAoH67GoDb41TDxvCNJlQ6hReZEuG6BOegeolNrCgZqNxmjRrC6R7Arekp1fYq 2ikjhSoMbPH6rX3EWN2VjiUj4khtbLUkqKBY0jIRDyIMV3fMh32mlmX/Esfo5ElBHmuxQa FnLsLFFzb53v/lY8put8+9x2/Wv25xDrRAda6I7Bu1ZJLOWpzZwVKDSAlIFHVvyamnkt5M m/T5QMXtv1N42d5NId4mSJiCeXnsi4POqNXYLG2Gv314e4/41/IjDSltZ7GDBw== ARC-Seal: i=1; s=key1; d=yhetil.org; t=1618671942; a=rsa-sha256; cv=none; b=uozT+w+rDgz7+mrtRn06MI8WxlwGxR2rcFvSl5aCepxwdi5oiD9eH8z3+tn96tD0I4K7G4 zLSQ93niZRsihM6mz4U5M6BtWOO/1yr+2W2Ki5gQDDvruuhCO+7jvF9UJkQ+z1SFzqHD/d s60qGgFV5ImB3UTE/dV5804IilbNr7FhIQzqZDmRpLbLjKy7NhVdXrdzgc12WbIM5MpgtI nbQmSKNCWE+soEophbolYV5XwKqek4ihg8fuGPQuE7ZbvcuP+S7vKci4fJ7T09vumWXMfX 0r7GLshLxN5pa51VD6Cq9YNEA5HWTseMaEVdtVkcUhpGPzNw3cnjT7qZtOP/1Q== ARC-Authentication-Results: i=1; aspmx1.migadu.com; dkim=none; dmarc=pass (policy=none) header.from=gnu.org; 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-Migadu-Spam-Score: -0.44 Authentication-Results: aspmx1.migadu.com; dkim=none; dmarc=pass (policy=none) header.from=gnu.org; 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-Migadu-Queue-Id: D090116119 X-Spam-Score: -0.44 X-Migadu-Scanner: scn0.migadu.com X-TUID: n4vx01d59QaA Hi, ilmu skribis: > To drive the point home: If the artefact has the same hash as it did befo= re then clearly the underlying change did not affect it. Early cut-off is t= herefore not possible in the case where the program being depended on is su= pposed to be used at runtime. > > This is at least how I am thinking about it, I think this would be a good= incremental improvement on the state of the art but it would still have th= ese limitations. What=E2=80=99s currently implemented is memoization: the hash (of the .drv = and that of the output(s)) is computed over all the inputs. Since the output file name (the one passed to =E2=80=9C./configure --prefix= =E2=80=9D & co.) appears in the build result 99% of the time, the content vary at least due to occurrences of the output file name. Thus, content comparison are not doable as is. What would help is content comparison _modulo_ output file name(s). But again, =E2=80=9Csame hash as it did before=E2=80=9D is a framing that d= oesn=E2=80=99t hold in a purely functional, stateless context. Ludo=E2=80=99.