Project.documentation_type is auto

[humitos]

We have 528 projects with the Project.documentation_type set in auto and this value is not allowed in the code.

This value is used, for example at: https://github.com/rtfd/readthedocs.org/blob/be4ff5b9c4fb6f8c4f8b093e98a1359491a52b1f/readthedocs/doc_builder/python_environments.py#L276

But the dictionary used to get the proper builder class doesn't have the auto value and make the build to fail:

https://github.com/rtfd/readthedocs.org/blob/be4ff5b9c4fb6f8c4f8b093e98a1359491a52b1f/readthedocs/doc_builder/loader.py#L15-L32

We do have a way to protect ourselves for this, but this is still happening in production.

https://github.com/rtfd/readthedocs.org/blob/be4ff5b9c4fb6f8c4f8b093e98a1359491a52b1f/readthedocs/projects/tasks.py#L429-L431

I suppose that this is still happening because of #3946 isn't deployed yet.

This doesn't seem to be too important, but just filling this issue to keep track of this and make sure that it doesn't happen anymore after that PR is deployed.

Ref: https://sentry.io/read-the-docs/readthedocs-org/issues/472212666/events/latest/

[agjohnson]

Sentry issue: READTHEDOCS-ORG-CWX

[agjohnson]

Lets target this for this release, I'm seeing a lot of new errors around this project type, including ^

[humitos]

To reproduce this, just change the Documentation Type to auto and the next build will fail.

[humitos]

it fails only in the immediate build, since it's automatically updated... but the build that updates it, fails.