On the other hand, I'm thinking if this is something that we want to do in the image or as a build command every time a RTD project builds.

@humitos Here's a link to the docker-stacks that we use in Jupyter and how we handle conda and conda-forge channel https://github.com/jupyter/docker-stacks/blob/master/base-notebook/Dockerfile#L66

@willingc great!

The only difference that I see is the --system that in RTD specific case I think won't change too much since the all the commands inside the docker image are ran by the docs user, but anyway I think we should use it :)

+1 Thanks @willingc -- Looks like we should steal the no auto upgrade bit too?

@ericholscher if we really want to have a pinned version, we should... otherwise it will upgrade on every conda env create

Read this: readthedocs/readthedocs.org#2566 (comment)

I would seriously consider readthedocs/readthedocs.org#2566 (comment) from @SylvainCorlay.

@humitos This should be targeting the release-2.x branch, I believe. I've gone ahead and updated it.

Gonna call this done, and merge it. We can track removing our version overrides for conda separately.