There is a koji plugin called "save-failed-tree", that allows you to get the buildtree of a failed build tarred up and downloaded.

This is a very useful feature for figuring out failed builds, especially on the more uncommon architectures like ppc64le and s390x.

This plugin currently is not installed on the CentOS Stream Koji, and if you try to download the buildtree you get.

$ koji -p stream save-failed-tree --full --task 3002979
* The save_failed_tree plugin appears to not be installed on the koji hub.  Please contact the administrator.

Please install the save_failed_tree plugin onto the CentOS Stream Koji instance.