Support Python 3.9

[cjolowicz]

Opening this issue to track when Python 3.9 support becomes available for documentation builds on Read the Docs. Python 3.9.0 was released on October 5, 2020.

For reference, the issue for the previous major Python release (3.8) was #6324. Support for Python 3.8 was added in #6654.

Thank you 🙇‍♂️

Details

• Read the Docs project URL: https://readthedocs.org/projects/cookiecutter-hypermodern-python-instance
• Build URL (if applicable): https://readthedocs.org/projects/cookiecutter-hypermodern-python-instance/builds/12066088/
• Read the Docs username (if applicable): cjolowicz

Expected Result

Documentation builds use Python 3.9 when this version is specified in .readthedocs.yml:

python:
  version: 3.9

Actual Result

The build fails with the following error message:

Error: Problem in your project's configuration. Invalid "python.version": expected one of (2, 2.7, 3, 3.5, 3.6, 3.7, 3.8, pypy3.5), got 3.9

[graingert]

it would be good to support 3.10dev at the same time

[humitos]

Python 3.9 should be included in our docker images. We have an issue opened for that at readthedocs/readthedocs-docker-images#140

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[ThiefMaster]

certainly not stale ;)

[graingert]

Bump

[staticdev]

@humitos I would like to add that all my projects are already building the docs with Python 3.9 and I didn't have any problem so far.

[ThiefMaster]

@staticdev So RTD now finally supports building with Python 3.9? Or are you using any workarounds to use 3.9?

[staticdev]

@ThiefMaster I didn't use any workaround, it just worked. Did you experience any problem?

[ThiefMaster]

I haven't tried again this year, but the last time I checked there was no Python 3.9 support on RTD, and when I had a quick look at your repos they still seem to use 3.8 in the RTD config file.

[oddlama]

Is there any update on the issue? Python 3.9 is now almost 5 months old.

[ThiefMaster]

readthedocs/readthedocs-docker-images#159 (comment)

This worked for me.

[humitos]

@oddlama as @ThiefMaster mentioned, using

build:
  image: testing

in your .readthedocs.yaml file is the way to go for now. Please, report any problem that you may find here as we are still testing this Docker image and Python version.

[oddlama]

Thanks! No problems thus far, worked perfectly without other adjustments.

[astrojuanlu]

Can this be closed then? (See also readthedocs/readthedocs-docker-images#172)

(Edit: bad copy-paste)

[ri-gilfanov]

The problem with Python 3.9 is still there.

Problem in your project's configuration. Invalid "python.version": expected one of (2, 2.7, 3, 3.5, 3.6, 3.7, 3.8, pypy3.5), got 3.9

[stsewd]

@ri-gilfanov see https://docs.readthedocs.io/en/stable/config-file/v2.html#build-beta-specification