Bug 646458 – sys-apps/portage: enable --dynamic-deps=y by default once again

• Product: Portage Development
• Status: RESOLVED FIXED

[Description Zac Medico 2018-02-03 01:42:18 UTC]

The disabling of dynamic deps by default in portage-2.3.20 has resulted in a lot of pushback, so I want to revert it until we've come up with a viable solution that does not involve rebuilds. Related things:

https://archives.gentoo.org/gentoo-dev/message/56987ae0bfb29403bedd12fe847d80a4
https://archives.gentoo.org/gentoo-dev/message/a88cfb0637ca1f3d781000471b9c8d35
https://bugs.gentoo.org/645550
https://bugs.gentoo.org/645780

I'm hoping that a tool can be created to apply dependency changes in-place, without rebuilding anything. It will be much like --dynamic-deps, but will persistently change the dependencies for installed packages an binary packages.

I've asked Michał Górny about the revert on IRC:

> [13:20:20] <zmedico> mgorny: also, how do you feel about reverting to --dynamic-deps=y by default for now? it's a big pain and I feel like we can do better with some more preparation.
> [13:27:51] <zmedico> It would be nice to have a tool that patches dependency changes in-place, especially since there's so much aversion to rebuilds
> [13:28:33] <zmedico> People would have nothing to complain about.
> [13:29:40] <zmedico> I don't enjoy listening to people complain :-)
> [13:32:08] <mgorny> zmedico: as long as developer don't use dynamic deps, i'm fine with it
> [13:32:33] <mgorny> but if developers throw excuses that they don't have to follow policy because it doesn't match portage defaults... and then insult QA members for trying to enforce it
> [13:33:11] <mgorny> zmedico: as for patches, i guess when they're reviewed + 1-2 days in case more urgent issues are found
> [13:33:27] <mgorny> we may also consider the version before them as earlier stable candidate
> [13:35:15] <zmedico> yeah that sould good
> [13:36:36] <zmedico> *sounds
> [14:06:58] <mgorny> as for updates, i don't see it happening
> [14:07:04] <mgorny> people have been talking about it for years
> [14:07:11] <mgorny> nobody came with any real proposal
> [14:07:22] <mgorny> our existing updates (pkgmoves) are complex and people screw them up a lot
> [14:07:35] <mgorny> depmoves would be more common, so that would make portage ultraslow and people will screw up even more

[Comment 1 Zac Medico 2018-02-03 02:57:55 UTC]

Patch posted for review:

https://archives.gentoo.org/gentoo-portage-dev/message/1af1404b7715e89a898f10c3f74a08a9
https://github.com/gentoo/portage/pull/249

[Comment 2 Larry the Git Cow 2018-02-03 03:07:52 UTC]

The bug has been referenced in the following commit(s):

https://gitweb.gentoo.org/proj/portage.git/commit/?id=a6671c73f3d1aa74789534e5eebccbca23b48656

commit a6671c73f3d1aa74789534e5eebccbca23b48656
Author:     Zac Medico <[e-mail]>
AuthorDate: 2018-02-03 01:45:21 +0000
Commit:     Zac Medico <[e-mail]>
CommitDate: 2018-02-03 02:21:28 +0000

    emerge: enable --dynamic-deps=y by default once again (bug 646458)
    
    There's been a lot of pushback involving the --dynamic-deps=n default.
    What we really need is a tool to apply dependency changes in-place,
    without the need for a rebuild.
    
    Reverts: 2905e1c2c28d ("Disable dynamic-deps by default")
    Bug: https://bugs.gentoo.org/646458

 man/emerge.1                          | 2 +-
 pym/_emerge/Scheduler.py              | 3 ++-
 pym/_emerge/create_depgraph_params.py | 6 +++---
 pym/_emerge/depgraph.py               | 7 +++----
 4 files changed, 9 insertions(+), 9 deletions(-)}

[Comment 3 Ulrich Müller 2018-02-03 08:00:03 UTC]

So the decision is that Portage will ignore PMS again?

[Comment 4 Zac Medico 2018-02-03 08:11:47 UTC]

We need a strategy for in-place dependency updates, because there are a lot of noisy people who aren't willing to accept rebuilds as the answer.

[Comment 5 Ulrich Müller 2018-02-03 08:48:41 UTC]

Actually, we have a council decision on this:

| The following policy was accepted by unanimous vote:
| "Maintainers must not assume that dynamic dependencies will be applied 
| by the package manager. When changing runtime dependencies the 
| maintainer should revision the ebuild if the changes are likely to 
| cause problems for end users."
https://projects.gentoo.org/council/meeting-logs/20151011-summary.txt

So as a maintainer, I should be able to rely on the fact the the package manager *won't* apply dynamic dependencies.

[Comment 6 Zac Medico 2018-02-03 09:04:00 UTC]

(In reply to Ulrich Müller from comment #5)
> Actually, we have a council decision on this:
> 
> | The following policy was accepted by unanimous vote:
> | "Maintainers must not assume that dynamic dependencies will be applied 
> | by the package manager. When changing runtime dependencies the 
> | maintainer should revision the ebuild if the changes are likely to 
> | cause problems for end users."
> https://projects.gentoo.org/council/meeting-logs/20151011-summary.txt
> 
> So as a maintainer, I should be able to rely on the fact the the package
> manager *won't* apply dynamic dependencies.

Ok, so let's force devs to use --dynamic-deps for some time, before we do it to users.

[Comment 7 Zac Medico 2018-02-03 09:04:47 UTC]

Of course I mean, force devs to use --dynamic-deps=n.

[Comment 8 Zac Medico 2018-02-03 09:12:49 UTC]

We could make the --dynamic-deps=n default conditional on USE="gentoo-dev", or something like that, and then tell developers that they have to enable it. If that's a success, then the dependency situation should improve to the point where it's usable for normal users.

[Comment 9 Zac Medico 2018-02-03 09:16:45 UTC]

Basically, it's not fair to unleash the --dynamic-deps=n default on our users until we prove that our devs will cooperate.

[Comment 10 Ulrich Müller 2018-02-03 09:20:34 UTC]

(In reply to Zac Medico from comment #7)
> Of course I mean, force devs to use --dynamic-deps=n.

I cannot think of any way how "not assume that dynamic dependencies will be applied by the package manager" could be read as to apply to developers' systems only.

[Comment 11 Zac Medico 2018-02-03 09:27:51 UTC]

(In reply to Ulrich Müller from comment #10)
> (In reply to Zac Medico from comment #7)
> > Of course I mean, force devs to use --dynamic-deps=n.
> 
> I cannot think of any way how "not assume that dynamic dependencies will be
> applied by the package manager" could be read as to apply to developers'
> systems only.

The strategy that I'm suggesting involves 2 phases:

1) Roll out a USE="gentoo-dev" flag that triggers the default --dynamic-deps=n setting.

2) After gentoo dev's have shown a willingness and ability to do the revbumps, roll out the default --dynamic-deps=n setting to regular users.