"Parallel mode" error strikes again

[alliter8]

Describe the bug

Even though Fix #6803: Disable parallel build on macOS and py38+ #6879 was implemented, I am once again receiving this error on Big Sur. (I did not experience an issue on Catalina, though I only started using Sphinx a few months ago on this Mac, which is long after those fixes were added.)

When attempting make html with the minimal Makefile from sphinx-quickstart, I get the following error:

Running Sphinx v3.5.4
For security reason, parallel mode is disabled on macOS and python3.8 and above. For more details, please read https://github.com/sphinx-doc/sphinx/issues/6803
make: *** [html] Error 2

I am not receiving this issue with the exact same repo on Windows or Linux.

To Reproduce

Steps to reproduce the behavior:

$ cd /path/to/repo
$ make html

Expected behavior

I expect the html to be built as it does on the other systems.

Your project

I cannot share this because it is proprietary.

Screenshots

sphinx parallel error

Environment info

• OS: Mac v11.2.3
• Python version: v3.9.3
• Sphinx version: v3.5.4 (Homebrew as recommended in official docs for Mac)
• Sphinx extensions: 'sphinx.ext.autodoc', 'sphinx.ext.autosectionlabel', 'sphinx.ext.graphviz', 'sphinx.ext.inheritance_diagram', 'sphinx.ext.intersphinx', 'sphinx.ext.ifconfig', 'sphinx.ext.mathjax', 'sphinx.ext.napoleon', 'sphinx.ext.todo'
• Extra tools: N/A

Additional context

Unfortunately, I have nothing else about why this is happening. I had hoped to come here and find a quick answer, lol.

[tk0miya]

Thank you for reporting. We need to reimplement the whole of the parallel build feature to do that.

Same as #6881. Closing.

[alliter8]

So, to be clear, this is not on the roadmap currently? Is there a workaround for Mac users?

[tk0miya]

Unfortunately, perfectly stalled. We need to scrap and build the whole of the feature. In details, we need to replace the thread model with process model. So it should be fully redesigned. And nobody work on it AFAIK.