From the logs:

Warning, treated as error:
/srv/docsbuild/3.8/cpython-zh-cn/Doc/c-api/bool.rst:33:<translated>:1:Inline interpreted text or phrase reference start-string without end-string.

To avoid this, in the french translation, we're using travis to check the build: https://github.com/python/python-docs-fr/blob/3.7/.travis.yml
You may not need pospell (don't know if it make sense or if it works well in zh-cn).