Michael Tremer wrote in Bugzilla:
Arne has found the issue in a new “hardening” feature in glibc developed by Intel. It is designed for modern processors, however did not check if it was compatible with i586 and therefore generated binary code which could not have been executed on those processors.
…
The core update will now be updated and can then be installed on i586 systems, too. We will not change the installation images.
I’ve tested this. No problems found, also with addons.
To be sure you get the new files you should delete files in /opt/pakfire/db/meta/ and /var/cache/pakfire/ , if you tried to install addons with the defective core149.