Build Image Upgrades

Starting this week, we’ll be deploying a new default image for our documentation build environments. This image will change the default Python versions that are supported.

We aren’t expecting any issues to arise from this change, but be sure to raise any issues on our issue tracker if you notice any strange behavior. The new build image supports Python 2.7 and Python 3.5, dropping support for Python 3.4. If you require access to Python 3.4, we suggest you sign up for access to our next beta image.

The next image for our build process is now being tested. This image will support multiple versions of Python: 2.7, 3.3, 3.4, 3.5, and 3.6. Instead of relying on the distribution’s versions of Python, multiple versions are instead installed from source, using pyenv.

If you’d like beta access to this build image for your projects, you can sign up here:


Users are now able to opt in to a build image that support Python 3.6, signing up for beta access is no longer required. For more information, see our blog post on Python 3.6 Support

We are slowly moving project configuration to our YAML configuration file, readthedocs.yml. Access to specific versions of Python will only be available using this configuration method, by specifying a python.version element.