Evaluate impact of upgrade to sphinx 2.0.0 and python 3.7 for building.

[stefanodavid]

python-sphinx 2.0.0 (currently in beta/RC stage) will drop support for python 2.7 and 3.5 and will require python 3.7. Check what version(s) currently support(s) rtd, what are their plans, and act accordingly.

[stefanodavid]

I locally already use a wrapper that calls sphinx-build using the python3.7 interpreter without any problem. This will avoid any problem with python 2.7's EOL from next January.
Sphinx 2.0.0 has been released and will be evaluated in the next months. Apparently, conf.py file will need a different syntax, therefore before upgrading it is necessary to make sure to update it as well.

[stefanodavid]

I upgraded Sphinx to 2.1.2 and it works; the wrapper seems to already use python3. I will try it on a vanilla system where there is no python 2 installed. Still to check support for python3 on RTD.

[stefanodavid]

I set the interpreter on rtd to python 3.x (which should be 3.7 if I am not mistaken), but they still use Sphinx 1.8.5.
There is however neither an error message, nor any warning, so it seems we're on the right trail! 👍

[stefanodavid]

After a bit of research, I found in the readthedocs repo, that issue 5604 is open for supporting Sphinx 2.0 on their side.

I think I am not using many Sphinx 2.0 features, (probably none at all), so unless I found serious errors in the builds on rtd, I won't be worried about this issue anymore. I close this issue for the time being.