Hi,

It seems the openstack-tox-docs job is broken in some projects because of the following

change made in Sphinx >= 5.0.0 .

 https://github.com/sphinx-doc/sphinx/commit/a3d09835522e6487cf93dcc871179db8d69e4180

We currently have Sphinx 4.5.0 in upper-constraints.txt but some projects (eg. Heat, Nova,

Neutron) are using only their own docs-constraints.txt and pull the latest version which is 5.0.1 .

IMO we need to fix the problem by the following two steps, but I'd appreciate

if anybody can share a better idea.

 1. Update tox.ini to honor upper-constraints.txt. This is needed in master and

     stable/branches as well.

 2. Update docs/source/conf.py to hard-code the language parameter to 'en'.

     This is required in master so that we can bump the upper version later.

Thank you,

Takashi Kajinami