https://pagure.io/koji/pull-request/4093 hits the older code in mavenBuild which expects some log files which are not present there thus failing the build in the upload phase.
Commit fccf4fa3 fixes this issue
Commit 51f5a4eb relates to this ticket
Metadata Update from @tkopecek: - Custom field Size adjusted to None - Issue tagged with: testing-ready
This issue has been migrated to Fedora Forge: https://forge.fedoraproject.org/koji/koji/issues/4273
Please continue any further discussion there.