There are two warnings generated by Sphinx:

/.../cpython/Doc/library/intro.rst:15: WARNING: inconsistent term references in translated message. original: [':keyword:`import`'], translated: []
/.../cpython/Doc/library/intro.rst:36: WARNING: inconsistent term references in translated message. original: [':mod:`random`', ':ref:`built-in-funcs`'], translated: []

It seems like there are redundant space inside the reference syntax, e.g. :keyword:`import` should not become :keyword: `import`.