http://koji.fedoraproject.org/koji/taskinfo?taskID=13164900 you can see that HEAD was not resolved to the git hash
This broke when config got split into the image-build subsection. Fix in PR #195.
image-build
This issue has been migrated to Fedora Forge: https://forge.fedoraproject.org/pungi/pungi/issues/193
Please continue any further discussion there.