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

[Zac Medico]

On 01/28/2018 08:34 PM, Alec Warner wrote:
>
>
> On Sun, Jan 28, 2018 at 8:10 PM, Zac Medico <zmedico@g.o
> <mailto:zmedico@g.o>> wrote:
>
>     On 01/28/2018 04:17 PM, Michael Orlitzky wrote:
>     > Since ::gentoo is the only repository governed by the PMS, can't we make
>     > repoman do this? The problem with requiring "repoman --force" for an
>     > in-place dependency change is that repoman generally won't have access
>     > to the unedited ebuild; but for ::gentoo, we can probably hack something
>     > together in git. Have it source the old and new ebuilds, and compare
>     > their dependency lists.
>
>     Yes I'm in favor of that, but it doesn't accomplish my current goal, as
>     I'll explain below.
>
>     > It won't work outside of a git repo, but it will work in the one place
>     > that really matters.
>
>     My goal for this patch is to provide a safety net for users, such that
>     they'll be automatically notified that the --changed-deps option is
>     available when needed to solve problems involving stale dependencies.
>     The reason behind this goal is that git commits flow directly to rsync
>     without any restriction, which makes users vulnerable to stale
>     dependencies, in the form of failed dependency calculations.
>
>
> What I would go along with is:
>
> 1) If we can determine the depgraph failed and

If we use depgraph failure as a condition, then we're ignoring
potentially missed updates due to stale dependencies. So, it's safer to
show the message regardless of depgraph failure, and that's what it does.

> 2) We can determine that dependencies changed.

Yes, _changed_deps_report returns silently if there are no changed
dependencies. Also, it returns silently with --quiet if none of the
packages with changed dependencies are in the graph.

Actually, if none of the packages with changed dependencies are in the
graph, then we can be silent even without --quiet because the emphasis
on filing bugs has been removed in PATCH v2. So, in PATCH v3, I'll make
it silent regardless of --quiet in this case.

> 3) Show a NOTE telling users about --changed-deps=y

This is in the HINT section, which is displayed if both --changed-deps
and --dynamic-deps are disabled in PATCH v2.

>
> But I'm not sure the patch does this today? I think it will trigger too
> aggressively. But ultimately I'm not against helping users work around this
> sort of breakage.

Do my responses above sound reasonable?
-- 
Thanks,
Zac