Когда я пытаюсь собрать документацию, используя make htmldocs в ядре Linux. Я получаю предупреждение ниже.
Warning: The Sphinx 'sphinx_rtd_theme' HTML theme was not found. Make sure you have the theme installed to produce pretty HTML output. Falling back to the default theme.
loading pickled environment... not yet created
building [mo]: targets for 0 po files that are out of date
building [html]: targets for 1088 source files that are out of date
Как мне это исправить?