I just rebased and tried tox in docs, and it worked for me. The install list was almost identical:

docs installed: alabaster==0.7.12,Babel==2.9.0,certifi==2020.11.8,chardet==3.0.4,docutils==0.15.2,dulwich==0.20.14,idna==2.10,imagesize==1.2.0,Jinja2==2.11.2,MarkupSafe==1.1.1,openstackdocstheme==2.2.7,os-api-ref==2.1.0,packaging==20.7,pbr==5.5.1,Pygments==2.7.2,pyparsing==2.4.7,pytz==2020.4,PyYAML==5.3.1,requests==2.25.0,six==1.15.0,snowballstemmer==2.0.0,Sphinx==3.3.1,sphinxcontrib-applehelp==1.0.2,sphinxcontrib-devhelp==1.0.2,sphinxcontrib-htmlhelp==1.0.3,sphinxcontrib-jsmath==1.0.1,sphinxcontrib-qthelp==1.0.3,sphinxcontrib-serializinghtml==1.1.4,urllib3==1.26.2

Have you tried wiping your .tox to start fresh, or do “tox -r” to reinstall?

From: Stone, Ronald <Ronald.Stone@windriver.com>
Sent: Wednesday, December 9, 2020 8:11 AM
To: starlingx-discuss@lists.starlingx.io
Subject: [Starlingx-discuss] doc-build-failures

Hi,

Starting yesterday several contributors to StarlingX docs can no longer successfully perform local doc builds:

$ tox -e docs

docs installed: alabaster==0.7.12,Babel==2.9.0,certifi==2020.11.8,chardet==3.0.4,colorama==0.4.4,docutils==0.15.2,dulwich==0.20.14,idna==2.10,imagesize==1.2.0,Jinja2==2.11.2,MarkupSafe==1.1.1,openstackdocstheme==2.2.7,os-api-ref==2.1.0,packaging==20.4,pbr==5.5.1,Pygments==2.7.2,pyparsing==2.4.7,pytz==2020.4,PyYAML==5.3.1,requests==2.25.0,six==1.15.0,snowballstemmer==2.0.0,Sphinx==3.3.1,sphinxcontrib-applehelp==1.0.2,sphinxcontrib-devhelp==1.0.2,sphinxcontrib-htmlhelp==1.0.3,sphinxcontrib-jsmath==1.0.1,sphinxcontrib-qthelp==1.0.3,sphinxcontrib-serializinghtml==1.1.4,urllib3==1.26.2

docs run-test-pre: PYTHONHASHSEED='925'

docs run-test: commands[0] | sphinx-build -a -E -W -d doc/build/doctrees -b html doc/source doc/build/html

ERROR: InvocationError for command could not find executable sphinx-build

___________________________________ summary ___________________________________

ERROR:   docs: commands failed

The executable sphinx-build.exe is missing from docs/.tox/docs/Scripts/

If manually restored, it is deleted the next time tox -e docs is run.

docs/.tox/log is empty.

Has there been a tox requirements change that would cause builds to start failing for multiple users simultaneously?

Any insights/suggestions appreciated.

Ron