Also happens for yum-utils-1.1.30-37.el6

reproducer:
0. # echo check_obsoletes=1 >> /etc/yum/pluginconf.d/priorities.conf
1. create repo1 with testA-1-1 pkg that obsoletes testB
2. create repo2 with testA-1-2 that obsoletes testB and
                with testC that requires testB
3. create repo3 with testB, set priority=1 for repo3
4. # yum install testC

+++ This bug was initially created as a clone of Bug #1269414 +++

Description of problem:
When yum-plugin-priorities is configured to check (blacklist) obsoleting packages ( echo check_obsoletes=1 >> /etc/yum/pluginconf.d/priorities.conf ), it will blacklist only the latest obsoleting package, not the older ones that may be present in some other repos.


Version-Release number of selected component (if applicable):
yum-plugin-priorities-1.1.31-33.el7.noarch

How reproducible:
Always

Steps to Reproduce:
1. Create a repo with 2 versions of a package that obsolete some other package
2. Bump the priority of the repo with the package that is being obsoleted
3. Try to install something that requires the obsoleted package with yum

Actual results:
Dependency problem because not all the obsoleted packages were masked.

Expected results:
The package installs fine.

Additional info:
Ceph upstream is hitting this when they are trying to install firefly branch on a rhel 7.1 host with epel enabled (*).

Here, base rhel 7.1 contains python-rados and python-rbd packages and epel contains python-rados and python-rbd packages. These packages obsolete python-ceph. The firefly branch of ceph does not split the python-ceph package into python-rados and python-rbd and uses the old python-ceph package. If you use the upstream repo for the firefly branch and bump its priority, 'yum install ceph' will fail because not all the python-rados and python-rbd packages were blacklisted/masked, only the latest one (as can be seen by yum install -v ceph).

(*) see upstream tracker http://tracker.ceph.com/issues/11104 for more details

...

--- Additional comment from Valentina Mukhamedzhanova on 2015-12-09 16:05:57 CET ---

Boris, I can't seem to be able to reproduce the problem using the suggested steps. I believe https://github.com/rpm-software-management/yum-utils/blob/master/plugins/priorities/priorities.py#L164 should take care of the case you're describing. Could you provide a tarball with repositories for reproducing the problem?

--- Additional comment from Boris Ranto on 2015-12-09 16:50:24 CET ---

Yeah, we do use yum-plugin-priorities. However, there is a bug that it fails to mask obsoleted packages if they occur twice (or more) in the repos. (e.g. base repo and testing repo)

Reproducer steps can be e.g. (contains two copies of ceph-common package in two separate repositories + link to upstream ceph repo):

wget http://lacrosse.corp.redhat.com/~branto/ceph.tar
cd /root/
tar -xvf ceph.tar
cp ceph.repo /etc/yum.repos.d/
yum install ceph # this will require some packages from epel so you need to have epel enabled as well

This will fail to install the older version of ceph packages even though there is priority=1 for the upstream repo.

Now, if you modify the ceph.repo file and disable the secondary local repo, it will install the packages just fine. Hence, the conclusion (confirmed by my last run with verbose yum output) that for obsoleted package the plugin masks only the latest package that it can find, not all of them.

btw: Please note that you need to have check_obsoletes=1 in /etc/yum/pluginconf.d/priorities.conf for the plugin to even mask the latest available package.

--- Additional comment from Valentina Mukhamedzhanova on 2015-12-10 16:26:12 CET ---

Boris, thank you for the reproducer! This should fix the problem - https://github.com/rpm-software-management/yum-utils/commit/834a4ff4f2752631252cff4e3b2ba87bee62965b

...