pidgin obsoleting itself

[Michael Schwendt]

On Wed, 9 Jun 2010 15:38:48 +0100, Stu wrote:

> I implemented it based on recommendations on the yum wiki that I saw
> someone else referred to in #fedora-devel :
> http://yum.baseurl.org/wiki/YumPackageUpdates#Packagesplit

Well, that's exactly an example where the two Obsoletes compete with
eachother. It works only partially. For an ordinary Yum update.
It fails for a Yum install. I warn about such competing Obsoletes, because
they strictly require the user to go the "yum -y update ; yum install ..."
route everytime they want to install an additional package. When talking
to some packagers related to broken deps, I've learned that some have
tried to add extra Obsoletes to make "yum install ..." pull latest updates
for new sub-packages just as "yum update ..." does. That has lead to bad
updates.

In case of pidgin-evolution, it only works because pidgin-evolution
also _requires_ (!) a specific release of pidgin. If that weren't the case,
a "yum install pidgin-evolution" would simply remove (= obsolete!) pidgin.
For a Yum install, an arbitrary package's Obsoletes are not considered
unless the package becomes part of the transaction set.
Competing Obsoletes => playing with fire.

> > You _cannot_ add _optional_ packages to a user's installation _without_
> > proper dependencies somewhere else. Attempts at trying to do that with
> > Obsoletes are invasive and prone to getting it completely wrong.
> 
> I thought that a reference from yum was a reasonably safe bet to be a
> good thing to follow.

It fails as outlined above.