kinto: documentation fails to build as of 2.1.2

[glasserc]

An automatic dependency bump (Kinto/kinto#2182) of Sphinx from 2.1.1 to 2.1.2 is failing. We receive the error:

Warning, treated as error:
/home/travis/build/Kinto/kinto/kinto/core/openapi.py:docstring of kinto.core.openapi.OpenAPI.generate::py:class reference target not found: dict

OpenAPI.generate doesn't actually have a docstring; it overrides https://github.com/Cornices/cornice.ext.swagger/blob/master/cornice_swagger/swagger.py#L398. This has :rtype: dict. We have other functions with this :rtype: dict field in our project and we have ("py:obj", "dict") on our nitpick_ignore list (since Sphinx 2.1.1; Kinto/kinto#2171).

$ git clone https://github.com/Kinto/kinto
$ cd kinto
$ make docs

Expected behavior
I didn't see anything in the changelog that would explain why this would fail.

Your project
https://github.com/Kinto/kinto/
https://travis-ci.org/Kinto/kinto/jobs/548162675 shows a failing build.

Environment info

• OS: Linux (container on TravisCI)
• Python version: 3.6.3
• Sphinx version: 2.1.2
• Sphinx extensions: sphinx.ext.autodoc, sphinxcontrib.httpdomain, sphinx.ext.extlinks, sphinx.ext.intersphinx; the sphinx_rtd_theme
• Extra tools: Readthedocs, Travis

[tk0miya]

Sorry for inconvenience. The behavior of 2.1.1 was not expected. And it was fixed at 2.1.2 (refs: #6478). So please update your nitpick_ignore setting to ("py:class", "dict").

[glasserc]

Thank you very much!