In Fedora 29, pungi requires python3-createrepo_c and makes obsolete createrepo library. It leads to a problem in gather.py where createrepo is imported. Specifically, in function _makeMetadata, the classes MetaDataConfig and MetaDataGenerator are used. So I guess there is a little adaptation to do with createrepo_c python bindings?
I went through the problem when using pungi-legacy subpackage under Fedora 29.
Commit f41c32e4 fixes this issue
Metadata Update from @lsedlar: - Issue set to the milestone: 4.1.32
This issue has been migrated to Fedora Forge: https://forge.fedoraproject.org/pungi/pungi/issues/1094
Please continue any further discussion there.