Re: [gentoo-portage-dev] [PATCH] emerge: add --changed-deps-report option (bug 645780)

[Michał Górny]

W dniu nie, 28.01.2018 o godzinie 10∶09 -0800, użytkownik Zac Medico
napisał:
> On 01/28/2018 09:35 AM, Alec Warner wrote:
> >
> >
> > On Sun, Jan 28, 2018 at 9:51 AM, Zac Medico <zmedico@g.o
> > <mailto:zmedico@g.o>> wrote:
> >
> >     The --dynamic-deps=n default causes confusion for users that are
> >     accustomed to dynamic deps, therefore add a --changed-deps-report
> >     option that is enabled by default (if --usepkgonly is not enabled).
> >
> >     The --quiet option will suppress the report if none of the packages
> >     having changed dependencies are in the dependency graph, since they
> >     are harmless in that case. If any of these packages *are* in the
> >     dependency graph, then --quiet suppresses the big NOTE section of
> >     the report, but the HINT section is still displayed since it might
> >     help users resolve problems that are solved by --changed-deps.
> >
> >     Example output is as follows:
> >
> >     !!! Detected ebuild dependency change(s) without revision bump:
> >
> >         net-misc/openssh-7.5_p1-r3::gentoo
> >         sys-fs/udisks-2.7.5::gentoo
> >
> >     NOTE: For the ebuild(s) listed above, a new revision may be
> >     warranted if there
> >           has been a dependency change with significant consequences.
> >     Refer to the
> >           following page of the Gentoo Development Guide for examples of
> >           circumstances that may qualify:
> >
> >
> >     https://devmanual.gentoo.org/general-concepts/ebuild-revisions/
> >     <https://devmanual.gentoo.org/general-concepts/ebuild-revisions/>
> >
> >           If circumstances qualify, please report a bug which specifies
> >     the current
> >           version of the ebuild listed above. Changes to ebuilds from
> >     the 'gentoo'
> >           repository (ending with '::gentoo') can be browsed in GitWeb:
> >
> >               https://gitweb.gentoo.org/repo/gentoo.git/
> >     <https://gitweb.gentoo.org/repo/gentoo.git/>
> >
> >           Use Gentoo's Bugzilla to report bugs only for the 'gentoo'
> >     repository:
> >
> >               https://bugs.gentoo.org/
> >
> >           In order to suppress reports about dependency changes, add
> >           --changed-deps-report=n to the EMERGE_DEFAULT_OPTS variable in
> >           '/etc/portage/make.conf'.
> >
> >     HINT: In order to avoid problems involving changed dependencies, use the
> >           --changed-deps option to automatically trigger rebuilds when
> >     changed
> >           dependencies are detected. Refer to the emerge man page for more
> >           information about this option.
> >
> >     Bug: https://bugs.gentoo.org/645780
> >
> >
> > I can't really support sending this large report to users.
> >
> > 1) Its fairly common practice today.
> > 2) All users will get the report.
> > 3) A subset of them will file bugs about the report.
> > 4) Devs make a decision about revbumping vs not; there doesn't seem to
> > be a way for devs to say "no this change is intentional, stop nagging
> > users."
>
> I think in practice we need to revbump for most changes. If the changes
> weren't worth propagating, then we wouldn't make them.

It's not about 'being worth propagating', it's about 'being worth
the rebuild to propagate'.

I've bumped dependency inside all LLVM ebuilds today. The change fixes
only problem that hits people who:

a. don't use --deep when upgrading,

b. use clang with LTO.

I can't say how many people were hit by it since 5.0.0 was introduced
but yesterday I've got the first (and only) report so far.

Yes, I could technically revbump and cause people to have to spend most
of the day rebuilding 1-2 versions of LLVM for change that doesn't make
any difference to them.

Yes, I could consider the change 'not worth making'. But why shouldn't I
improve stuff for our users when it doesn't harm to do so?

But with your suggested solution, now we no longer have the choice
'revbump or not revbump'. Now we have a choice between forcing people to
rebuild via revbump or forcing people to get verbose report that most
likely will result in meaningless bug report and/or rebuild. So I end up
having a choice between 'force people to rebuild' or 'not fix minor bugs
at all'.

-- 
Best regards,
Michał Górny