def _get_target_source_packages(self, component: str):
        ''' Get mapping of all sources packages in a suite and its parent suite. '''
        with session_scope() as session:
            target_suite = session.query(ArchiveSuite) \
                                  .filter(ArchiveSuite.name == self._target_suite_name).one()
            suite_pkgmap = self._get_repo_source_package_map(self._target_repo,
                                                             target_suite.name,
                                                             component)
            if target_suite.parent:
                # we have a parent suite
                parent_map = self._get_repo_source_package_map(self._target_repo,
                                                               target_suite.parent.name,
                                                               component)

                # merge the two arrays, keeping only the latest versions
                suite_pkgmap = make_newest_packages_dict(list(parent_map.values()) + list(suite_pkgmap.values()))

        return suite_pkgmap