Red Hat Bugzilla – Bug 1269414
yum-plugin-priorities does not blacklist all the obsoleted packages
Last modified: 2016-11-03 20:13:54 EDT
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):
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
Dependency problem because not all the obsoleted packages were masked.
The package installs fine.
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
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?
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):
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.
Boris, thank you for the reproducer! This should fix the problem - https://github.com/rpm-software-management/yum-utils/commit/834a4ff4f2752631252cff4e3b2ba87bee62965b
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.
For information on the advisory, and where to find the updated
files, follow the link below.
If the solution does not work for you, open a new bug report.