[CentOS] What's wrong with yum-priorities?

[Jim Perrin]

On Sun, Nov 22, 2009 at 2:27 PM, Dennis Kibbe <dennisk at sahuaro.us> wrote:
> "The upstream maintainer of yum, Seth Vidal, had the following to say
> about 'yum priorities' in September 2009:
>
> Gosh, I hope people do not set up yum priorities. There are so many things
> about priorities that make me cringe all over. It could just be that it
> reminds me of apt 'pinning' and that makes me want to hurl."
>
> This note was placed on the wiki (PackageManagement/Yum?Priorities)
> without any explanation why yum-priorities isn't a good idea.
>
> yum-priorities doesn't appear in RHEL 5.4 but protectbase does. Is that
> the better choice and if so why?


It's not really yum-priorities, so much as what it does and how it acts.

In a perfect world, you would not need to add additional repositories
to get all the software you want. However that's rarely the case.

What ends up happening is that you have multiple repositories that
provide the same thing, sometimes under different names. You end up
mixing dependencies between repositories, so some things are
protected, some pull in deps from the wrong repository... fire and
brimstone, dead rising from graves, dogs and cats start living
together. The whole mess introduces some really odd logic edge cases
for yum that should in theory never be encountered. It's basically a
software solution to a management problem.

If you're careful about what you're doing, it's fine. If you enable
every single repository you can find for centos, it's going to end up
causing you some issues.

The long and short of it boils down to how rpm is implemented, how
different packagers package things, and how ignorant the average user
wants to be to the internal workings of the system. Most folks just to
have it work, end of story.  Yum gets caught in the middle, and
priorities, while good, is a hack that allows user freedom that comes
with some really ugly thinking.

-- 
During times of universal deceit, telling the truth becomes a revolutionary act.
George Orwell