It is not possible to properly do sphinx-build
I don't know if you are aware of this, but we are having problems with the SSL certificates when we do the intersphinx:
Look at this build https://gitlab.idiap.ch/bob/bob.db.pericrosseye/builds/45179
Warning, treated as error:
WARNING: intersphinx inventory 'https://pythonhosted.org/six/objects.inv' not fetchable due to <class 'urllib2.URLError'>: <urlopen error [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:590)>
(16:53:19) Error: Command Failed "./bin/sphinx-build -W doc sphinx"
Probably that's why this build is failling (https://gitlab.idiap.ch/bob/bob.nightlies/builds/45158).
cheers