Description of problem: The logrotate configuration that comes with dnf specifies both an age (yearly) and a size (30k). But according to the manual, time intervals and a "size" are mutually exclusive. Maybe the intention was to specify "maxsize"?
Thanks for the report, fixed in the upstream.
dnf-plugins-core-0.1.5-1.fc21,hawkey-0.5.3-2.fc21,dnf-0.6.4-1.fc21 has been submitted as an update for Fedora 21. https://admin.fedoraproject.org/updates/dnf-plugins-core-0.1.5-1.fc21,hawkey-0.5.3-2.fc21,dnf-0.6.4-1.fc21
Package hawkey-0.5.3-2.fc21, dnf-plugins-core-0.1.5-1.fc21, dnf-0.6.4-1.fc21: * should fix your issue, * was pushed to the Fedora 21 testing repository, * should be available at your local mirror within two days. Update it with: # su -c 'yum update --enablerepo=updates-testing hawkey-0.5.3-2.fc21 dnf-plugins-core-0.1.5-1.fc21 dnf-0.6.4-1.fc21' as soon as you are able to. Please go to the following url: https://admin.fedoraproject.org/updates/FEDORA-2015-2139/dnf-plugins-core-0.1.5-1.fc21,hawkey-0.5.3-2.fc21,dnf-0.6.4-1.fc21 then log in and leave karma (feedback).
hawkey-0.5.3-2.fc21, dnf-plugins-core-0.1.5-1.fc21, dnf-0.6.4-1.fc21 has been pushed to the Fedora 21 stable repository. If problems still persist, please make note of it in this bug report.