Nitpick - in Katello we were able to put this into the katello-configure directory for each installer run. Users are often re-running our puppet installer, thus this could easily overwrite the initial error they received during the first run. At least if we can rotate somehow - some poors-man-rotating:

    test -f %{_localstatedir}/log/%{name}/db_migrate.log && mv %{_localstatedir}/log/%{name}/db_migrate.log-$(date +%Y-%m-%d_%H:%M:%S)