def _get_query_variables(repo_owner, repo_name, family_name, reference='refs/heads/main'):
  """
  call like: get_query_variables('google', 'fonts', 'gelasio')

  reference: see $ git help rev-parse
            and git help revisions
            and https://git-scm.com/book/en/v2/Git-Internals-Git-References
  For a branch called "main", "refs/heads/main" is best
  but "main" would work as well.
  Tag names work as well, ideally "ref/tags/v0.6.8" but "v0.6.8" would
  work too. The full name is less ambiguous.
  """
  return {
    'repoOwner': repo_owner,
    'repoName': repo_name,
    'reference': reference,
    'oflDir': f'{reference}:ofl/{family_name}',
    'apacheDir': f'{reference}:apache/{family_name}',
    'uflDir': f'{reference}:ufl/{family_name}'
  }