Bug#664209: apt_preferences: package of higher prio not choosen?!
Hello,
On Fri, Mar 16, 2012 at 22:54, Christoph Anton Mitterer
<calestyo@scientia.net> wrote:
> On Fri, 2012-03-16 at 18:54 +0100, David Kalnischkies wrote:
>> For these two we need to choose one to be above the other, for us it is the
>> version which is parsed at first, so move the deb-line for your archive above
>> the one for debian and you should be "fine".
>
> ...it's _really_ strange that this happens even though you set a higher
> priority?!
>
> I mean a) what the manpage says, by the words I've quoted before is that
> first it doesn't downgrade, then it takes the highest priority version
> (which would be mine in my example)...
> So this must mean that reinstalling the same version is considered as
> downgrading...
As i said, the versions aren't equal just because you have used the
same version number. Just because you paint all your cars red
doesn't mean that all of them are equal, they might all be red now,
but the engine doesn't magically change with the color, too -- especially
as yourself don't want to have them treated as equal as you want your version
installed, but equal would mean that the debian version is just as good…
Also, your description as reinstall is wrong: The version you want to have
installed is not only not installed, but also below the version which is
installed, so this is a downgrade and not a reinstall. That it doesn't change
the versionnumber (color) isn't enough to convince APT that is is the
same version (car) - and rightly so: Your red trabant doesn't replace your
red ferrari even through both are cars and both are red.
And in a world in which you order your red cars by age it doesn't make
a difference that you have a higher preference for your ferrari, it's still
newer than your trabant so it is behind. Why would anyone order by age you
might ask? Easy, age is objective - preference might change at any time
causing time-intensive reordering as you have a lot of garages (packages)
with different cars (versions).
(simply put, 'apt-get update' has to decide on the order of versions which
will be used by the following apt-* operations and as people change
their preference all the time we order by age aka first-seen)
Best regards
David Kalnischkies
Reply to: