F15 preupgrade: lots of uneraseable dupes

[suvayu ali]

Hi Bruno and Craig,

On Tue, Oct 11, 2011 at 2:26 PM, Bruno Wolff III <bruno at wolff.to> wrote:
> On Tue, Oct 11, 2011 at 12:11:21 +0200,
>  suvayu ali <fatkasuvayu+linux at gmail.com> wrote:
>>
>> Just wanted a clarification on that statement. I thought the safer way
>> was to disable all the community repositories before using something
>> like yum upgrade or preupgrade. That way any hidden packaging bug in
>> community packages don't come in the way of the distro upgrade. After
>> the upgrade is finished, all one has to do is enable the repos again
>> and do a simple yum update, followed by a distro-sync with all repos
>> enabled. Could you clarify why you think upgrading with them enabled
>> is better?
>
> Because you won't allow upgrades of the external packages, and by blocking
> those updates you can pin Fedora packages they are dependent on.

I thought yum doesn't do these kind of reverse dependency checks (the
reason remove-with-leaves is not reliable)? Or are you talking about
situations when an external package has a hard dependency like this:

external-1.00 requires = fedora-pkg1-1.00 instead of external-1.00
requires >= fedora-pkg1-1.00?


However it seems to me I might have misunderstood how dependencies
work with yum/rpm. In my understanding, all packages an external
package depends on is pulled in while installation. During an update
such a pulled in package can be updated without the external package
needing an update as long as it requires the dependency with a >=
fedora-pkg-version. Is this a correct understanding?

Thanks a lot for taking the time to explain. :)

-- 
Suvayu

Open source is the future. It sets us free.