As of koji 1.16.1, the split_debuginfo argument is required for a dist-repo task (it didn't exist before). If it's not passed, it results in kojid throwing an exception and erroring out the task: https://koji.fedoraproject.org/koji/taskinfo?taskID=30041886 .
split_debuginfo
A suggested fix is in #1115.
Metadata Update from @tkopecek: - Issue set to the milestone: 1.17
Commit 0784a5eb fixes this issue
Commit 4ed093ea fixes this issue
This issue has been migrated to Fedora Forge: https://forge.fedoraproject.org/koji/koji/issues/1114
Please continue any further discussion there.