Please read
pungi prototype wiki page for general overview <https://fedoraproject.org/wiki/Modularity_Working_Group/prototype/pungi>
In lkocman's prototype pungi was split into following:
pungi-gather-prototype (dnf based depsolver) which takes modulemd yaml file as input and generates directory with list of neveras (connected with json {'rpms' : file_with_nevras , ...}'
pungi-createrepo-prototype (dnf/repodata based linker and createrepo trigger) - output is directory with repodata + rpmanifest, temporarily identified by fm-metadata.yaml