---
version: 2

sphinx:
  configuration: docs/conf.py

# Don't build any extra formats, HTML and JSON will
# always be built by default.
formats: []

python:
  version: 3.9
  install:
  - requirements: docs/requirements.txt

---
version: 2

build:
  image: testing

sphinx:
  configuration: docs/conf.py

# Don't build any extra formats, HTML and JSON will
# always be built by default.
formats: []

python:
  version: 3.9
  install:
  - requirements: docs/requirements.txt

Switch from stable to testing build image.
Switch from stable to testing build image.

See:

- https://github.com/readthedocs/readthedocs-docker-images/pull/172/files
- https://github.com/readthedocs/readthedocs-docker-images/pull/159