On Wed, Aug 7, 2019 at 10:01 AM John Baldwin <j...@freebsd.org> 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. > I'm with John here: the dirty tree stuff is too fragile for the diversity of development environments that are typical on -current, but not typical on -stable. We should not revert this. Warner _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
