Pinning sphinx version not working for conda install

[sjrowlinson]

Details

• Read the Docs project URL: https://readthedocs.org/projects/finesse/
• Build URL (if applicable): https://readthedocs.org/projects/finesse/builds/10565374/
• Read the Docs username (if applicable): sjrowlinson

Expected Result

Pinning sphinx version at 2.3.1 as per the environment.yml file in the project:

Actual Result

Build process seems to be ignoring this and just installing latest Sphinx release anyway:

This results in the build failing due to a time out as Sphinx 2.4.0 seems to be very slow (which is why I want to pin to 2.3.1 for now).

[humitos]

Hi! I'm going to close this one as duplicated of #3829 and I'm going to apply the Feature Flag mentioned on #3829 (comment)

Feel free to re-open if this does not work.

[humitos]

You may probably need to wipe the version's environment first.