Changelog for R-udunits2-0.13-2.fc31.x86_64.rpm :

* Wed Jul 24 2019 Fedora Release Engineering - 0.13-2- Rebuilt for https://fedoraproject.org/wiki/Fedora_31_Mass_Rebuild
* Sun Mar 10 2019 Elliott Sales de Andrade - 0.13-1- initial package for Fedora