Re: [gentoo-dev] unsanctioned python 2.7 crusade

[Alexis Ballier]

On Fri, 2019-12-06 at 21:28 +0100, Thomas Deutschmann wrote:
> On 2019-12-06 21:10, Andreas Sturmlechner wrote:
> > Just so we're on the same page, a recent example of what some
> > people
> > suggesting to keep py27 ad nauseam are asking users to deal with:
> > [...]
> > WARNING: One or more updates/rebuilds have been skipped due to a
> > dependency
> > conflict:
>
> Yes, like said, at some point you cannot prevent that. Remember when
> I
> bumped libvpx to v1.8.0 and people yelled at me because they are now
> seeing that message all the time (If you are using gnome you probably
> know the same msg which triggers for unicode stuff which I am also
> responsible for) because I bumped that package but not everything
> supports that version yet?


For having maintained packages that often have this issue for years, I
must say this is a very bad idea: You are asking (or doing yourself)
consumer packages to have < deps on your package. This falsely gives
the impression that the non-latest version is still maintained. This
also makes removing this old version very error prone (we do have tools
to check for that but those are not in the standard workflow). Not sure
how portage handles this, but negative deps (<, =, ! & co) are much
harder to solve than purely positive ones -- PM probably uses some
heuristics but then this has some limitations and if the number of such
deps grows too much it may fail to solve them or do the right thing.

I think it is a much better way to package.mask the newest version of
your lib until all consumers work with it, or those that don't are
masked. This is how we handled such transitions before portage improved
its handling of negative deps and is IMHO still better.


Alexis.