docs: def ostree_init(self, release):
          """Initialize the OSTree for a release"""
          out = release['output_dir'].rstrip('/')
          base = os.path.dirname(out)
          if not os.path.isdir(base):
              self.log.info('Creating %s', base)
              os.makedirs(base, mode=0755)
          if not os.path.isdir(out):
              self.mock_chroot(release, release['ostree_init'])