From mboxrd@z Thu Jan 1 00:00:00 1970 X-GM-THRID: 6520199916203016192 X-Received: by 10.80.243.144 with SMTP id g16mr3014117edm.11.1518428480522; Mon, 12 Feb 2018 01:41:20 -0800 (PST) X-BeenThere: isar-users@googlegroups.com Received: by 10.80.170.50 with SMTP id o47ls6113745edc.3.gmail; Mon, 12 Feb 2018 01:41:19 -0800 (PST) X-Google-Smtp-Source: AH8x2243QnKFzv1ZGjRm0duu/ph/pYynRnvqyWYCMKHLpD0gkkm9PJRT7k56qOrEWkyKZeZXIDzt X-Received: by 10.80.202.201 with SMTP id f9mr455447edi.12.1518428479727; Mon, 12 Feb 2018 01:41:19 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1518428479; cv=none; d=google.com; s=arc-20160816; b=xGpSOvwR3Ogjz7UOBDc6DqBN4+W9wq+9JXw2PzBpPqhgfH60Dyg5fVPERgF+qcwTmR NbCdPHHfFS+GOfX8UzSI3XKYWm5kYy3hjxpYj7FGNwg3MwT3wDmFxzE1VrgXGyb2/hn9 CmtlgETcizrFSjrPqHoADrAGrq+yKEXHkA2vz5zbdqPJQnSgAePh23Y5nnmxxnFAiog3 QUFJIfLuJGejmWq9+XwbPu1n469RhV0POB7KnkXGsl1DFcadzS9HhPAceMhpHEW5r6o/ W0nBcIKr9gJdmRoXk+sIWUOL2xr5QU8iWlZj8OrYk1nKVL+bYIgKE+Es0OjWdRGOcsDp CH/w== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-transfer-encoding:content-language:in-reply-to:mime-version :user-agent:date:message-id:from:references:to:subject :arc-authentication-results; bh=QtFwNaGHuEu5cauGICmnx6lJokHiCzlEHpDRS44I3+c=; b=HMuY9XK4SfzpnL9kt9oAOq4LsQacGd9N3gwC67x502xqbOPPHrXdZHRb9pi9EQ6xO4 Zgqq6hkEGrNRlTFwMP19Wael4nlPl9PE5AuaDmSB4HZX1CCNt8S3g+5EXZ76McPUC0/9 zuxofxKMLvlvb0jvHltWjSLIBRUh6vmHlAz4PFBZAdEhug4Ax4aqDXRxo5D8hjxQ/2QT dTh6GVZLnRfRLSNO6bRbWCdnMVcHbFYOXxWuCJ+5Bg19l8EY8FZWAGxR+VD8ylXCp73x AmBlEunju5CSD9YtT85GcgOoVHd0Dcmhwkqkq+FYDTsgMWXw/bDAWWKI3BkPLmrUEhmK xodQ== ARC-Authentication-Results: i=1; gmr-mx.google.com; spf=pass (google.com: domain of jan.kiszka@siemens.com designates 192.35.17.28 as permitted sender) smtp.mailfrom=jan.kiszka@siemens.com Return-Path: Received: from goliath.siemens.de (goliath.siemens.de. [192.35.17.28]) by gmr-mx.google.com with ESMTPS id v28si417703edd.3.2018.02.12.01.41.19 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 12 Feb 2018 01:41:19 -0800 (PST) Received-SPF: pass (google.com: domain of jan.kiszka@siemens.com designates 192.35.17.28 as permitted sender) client-ip=192.35.17.28; Authentication-Results: gmr-mx.google.com; spf=pass (google.com: domain of jan.kiszka@siemens.com designates 192.35.17.28 as permitted sender) smtp.mailfrom=jan.kiszka@siemens.com Received: from mail3.siemens.de (mail3.siemens.de [139.25.208.14]) by goliath.siemens.de (8.15.2/8.15.2) with ESMTPS id w1C9fJTJ009725 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 12 Feb 2018 10:41:19 +0100 Received: from [139.25.68.37] (md1q0hnc.ad001.siemens.net [139.25.68.37] (may be forged)) by mail3.siemens.de (8.15.2/8.15.2) with ESMTP id w1C9fJRT030933; Mon, 12 Feb 2018 10:41:19 +0100 Subject: Re: [PATCH v4 2/8] Prioritize isar-apt repo over all others To: Alexander Smirnov , isar-users References: From: Jan Kiszka Message-ID: <136df397-5fce-9f50-fd74-f35f038fbda2@siemens.com> Date: Mon, 12 Feb 2018 10:41:17 +0100 User-Agent: Mozilla/5.0 (X11; U; Linux i686 (x86_64); de; rv:1.8.1.12) Gecko/20080226 SUSE/2.0.0.12-1.1 Thunderbird/2.0.0.12 Mnenhy/0.7.5.666 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-TUID: AXH4bWVrvp4y On 2018-02-12 10:33, Alexander Smirnov wrote: > On 02/11/2018 06:25 PM, Jan Kiszka wrote: >> From: Jan Kiszka >> >> This ensures that we can override packages from upstream Debian or other >> external sources with our self-built versions. We achieve this for now >> by asking multistrap to drop a preferences file for the buildchroot so >> that dependency installations use the right priority. For the image >> build, this does not work because all packages are pull during the >> bootstrap. Therefore, we set aptdefaultrelease to isar to ensure that >> our repo gets the higher priority. >> > > I'm not sure that I completely understand this. What is the use-case for > this? If you build your own copy of upstream package, this > prioritization could be resolved by specifying suffix to version. Simple example: custom kernel build of linux-cip This generates a package called linux-image-amd64 (for amd64 as target), and that may have a version < debian's kernel. Now, if we do not prioritize isar-apt over upstream, the upstream kernel is taken, even when you switched PREFERRED_PROVIDER (in fact, the build will break when that virtual package linux-cip is selected but can't be installed due to the version preference "newest"). > > For me this approach looks like a good way to have unexpected troubles > like the following: > > 1. You pick current glibc from upstream distro XYZ, let's say v1.0. > 2. Patch it and put glibc-v1.0-isar to isar-apt. > 3. Wait for some time until glibc is updated in upstream, let's say to > v1.1. > 4. Due to glibc-v1.0-isar is set to be preferred, it's going to be > installed. But glibc is the core library in distro, and lots of packages > in XYZ now require glibc-v1.1. So even if you will be able to generate > image, you can't guarantee it works correctly... Well, sure, no one takes away the task from you of properly maintaining the recipes when upstream updates happen (and you pull them into your reproducible build). Jan