From owner-svn-src-head@freebsd.org Wed Aug 7 16:58:10 2019 Return-Path: Delivered-To: svn-src-head@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 8AC9FB0D77; Wed, 7 Aug 2019 16:58:10 +0000 (UTC) (envelope-from pfg@FreeBSD.org) Received: from smtp.freebsd.org (smtp.freebsd.org [96.47.72.83]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "smtp.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 463d4239F0z40xL; Wed, 7 Aug 2019 16:58:10 +0000 (UTC) (envelope-from pfg@FreeBSD.org) Received: from [192.168.0.5] (unknown [181.52.72.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client did not present a certificate) (Authenticated sender: pfg) by smtp.freebsd.org (Postfix) with ESMTPSA id C031315A91; Wed, 7 Aug 2019 16:58:09 +0000 (UTC) (envelope-from pfg@FreeBSD.org) Subject: Re: svn commit: r350550 - head/share/mk To: src-committers@freebsd.org Cc: svn-src-all@freebsd.org, svn-src-head@freebsd.org, freebsd-hackers@freebsd.org, freebsd-arch@freebsd.org References: <201908030106.x7316Ibx078529@repo.freebsd.org> <20190806165614.GA41295@FreeBSD.org> <4e4d30b2-4801-2e53-6f26-49cb350445ec@FreeBSD.org> From: Pedro Giffuni Organization: FreeBSD Message-ID: <86621ce5-3a8d-2e22-f146-3b0cc8252124@FreeBSD.org> Date: Wed, 7 Aug 2019 11:58:08 -0500 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <4e4d30b2-4801-2e53-6f26-49cb350445ec@FreeBSD.org> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 07 Aug 2019 16:58:10 -0000 On 07/08/2019 11:00, John Baldwin wrote: > On 8/6/19 9:56 AM, Glen Barber wrote: >> On Sat, Aug 03, 2019 at 01:06:18AM +0000, John Baldwin wrote: >>> Author: jhb >>> Date: Sat Aug 3 01:06:17 2019 >>> New Revision: 350550 >>> URL: https://svnweb.freebsd.org/changeset/base/350550 >>> >>> Log: >>> Flip REPRODUCIBLE_BUILD back to off by default in head. >>> >>> Having the full uname output can be useful on head even with >>> unmodified trees or trees that newvers.sh fails to recognize as >>> modified. >>> >>> Reviewed by: emaste >>> Differential Revision: https://reviews.freebsd.org/D20895 >>> >> I would like to request this commit be reverted. While the original >> commit message to enable this knob stated the commit would be reverted >> after stable/12 branched, I have seen no public complaints about >> enabling REPRODUCIBLE_BUILD by default (and quite honestly, do not see >> the benefit of disabling it by default -- why wouldn't we want >> reproducibility?). >> >> To me, this feels like a step backwards, with no tangible benefit. >> Note, newvers.sh does properly detect a modified tree if it can find >> the VCS metadata directory (i.e., .git, .svn) -- I know this because >> I personally helped with it. >> >> In my opinion, those that want the non-reproducible metadata included in >> output from 'uname -a' should set WITHOUT_REPRODUCIBLE_BUILDS in their >> src.conf. Turning off a sane default for the benefit of what I suspect >> is likely a short list of use cases feels like a step in the wrong >> direction. > My arguments for flipping this in head (and head only) are that the data > provided in uname -a when this is disabled is useful for development, and > that in head we do tailor settings towards development (e.g. GENERIC in > head vs GENERIC in stable). > > The logic to handle modified trees has an inherent assumption that I think > is false, at least for my workflow and I suspect many others. I do builds > and tests of kernels on separate machines (VMs or bare metal) from where I > use VCS to manage sources so that a kernel crash doesn't toast my source > tree. The trees are then shared to the build/test machines via NFS. As > a result, the build/test machines are not always able to detect that the > tree is modified either because a subset of the checkout is exported via > NFS, or the VCS tool isn't installed on the build/test machines because > they are generally barebones systems with only a base installed. This > does mean that flipping the knob off doesn't provide all of the same info, > but it does provide the path, and the path matters because 'kgdb -n last' > uses it, and because if you use separate directories for separate projects > (e.g. git worktrees), then the path tells you which test kernel you booted. > (It is not uncommon for me to have several test projects in flight on a > single test machine for different branches.) > > In the original discussion on arch, we collectively recognized that > developer builds vs release builds were different and needed different > defaults. The compromise reached at that time was to depend on the VCS > to detect developer builds to choose the policy. What I have found is that > in practice for at least my workflow that doesn't actually work. I posit > that the majority of kernels built from head are developer builds, not > releases, and that the default should cater to that. You could also always > patch release.sh to set WITH_REPRODUCIBLE_BUILD in the environment which I > think would give a more accurate sense of when builds are releases or not. > > However, I will yield to whatever the consensus is. +1 keeping metadata in head.