Limitations
Pre-init options
Some options are read by Sphinx before any extension is set up, so changing their values after that won’t have the same effect. These options are:
They should be defined outside the multiproject_projects option,
but you can still change these per-project,
see Manually changing settings based on the current project.
app.confdir vs app.srcdir
The value of app.confdir
will always be the path of the shared conf.py file,
some extensions/themes may assume that this is the same as
app.srcdir,
which can result in some unexpected problems.
The extension/theme shouldn’t assume that the configuration directory is the same as the source directory.
Read the Docs configuration file
Read the Docs doesn’t support having more than one configuration file in your repository.
This is a problem if your projects require some specific and incompatible settings, like a different Python version, different requirements, or different search settings.