I've got the latest from https://git.centos.org/centos/centpkg/c/167cc2312fa7fb896e7c9c2f190dd240ed0d41d8?branch=develop

Author: Carl George <carl@george.computer>
Date:   Fri Apr 16 17:40:10 2021 -0500
 
    Bump to version 0.6.3
Which version of centpkg do you have? We updated 0.6.3-1 (possibly still in updates-testing) to include publicly accessible URLs.
 
--Brian