code: def fetch_git_package(self, config):
          
          # only loading git here when needed to avoid load errors on systems
          # without git installed
          from git import Repo
  
          ref = self.determine_git_ref(config)
          dir_name = self.sanitize_git_path(uri=config['uri'], ref=ref)
          cached_dir_path = os.path.join(self.package_cache_dir, dir_name)
  
          # We can skip cloning the repo if it's already been cached
          if not os.path.isdir(cached_dir_path):
              logger.debug("Remote repo %s does not appear to have been "
                           "previously downloaded - starting clone to %s",
                           config['uri'],
                           cached_dir_path)
              tmp_dir = tempfile.mkdtemp(prefix='stacker')
              try:
                  tmp_repo_path = os.path.join(tmp_dir, dir_name)
                  with Repo.clone_from(config['uri'], tmp_repo_path) as repo:
                      repo.head.reference = ref
                      repo.head.reset(index=True, working_tree=True)
                  shutil.move(tmp_repo_path, self.package_cache_dir)
              finally:
                  shutil.rmtree(tmp_dir)
          else:
              logger.debug("Remote repo %s appears to have been previously "
                           "cloned to %s -- bypassing download",
                           config['uri'],
                           cached_dir_path)
  
          # Update sys.path & merge in remote configs (if necessary)
          self.update_paths_and_config(config=config,
                                       pkg_dir_name=dir_name)
docs: Make a remote git repository available for local use.
  
          Args:
              config (dict): git config dictionary