Sphinx start new itom application during build

[Johann Krauter]

When Sphinx > 6 is used to build the itom website with a more modern theme (e.g.https://github.com/bashtage/sphinx-material) an additional itom applicaiton is started. The working itom application stays in a endless loop. Debugging shows that Sphinx internally starts a parallel application in the contextlib package.

However the MLD_theme of the itom website shall be changed because the theme is not more maintained as mentioned on the github site https://github.com/google/material-design-lite.

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[M. Gronle]

The problem is, that itom does not fully support the Python multiprocessing package.

To improve the multiprocessing support, it is necessary to tell multiprocessing about the path to the python.exe or pythonw.exe (no command line displayed):

import multiprocessing as mp

mp.set_executable(os.path.join(sys.exec_prefix, 'python.exe'))

However, this does not solve this issue. This issue occurs, if one wants to use the sphinx-immaterial theme. If this is part of the extension list of the conf.py, it is loaded and during the load, its submodule postprocess_html is loaded:

During this load, a multiprocessing.Manager is opened. Here an external Python server is opened, that tries to communicate with the main instance (here: itom) using a in/out pipe via a virtual file. This seems not to work within an embedded Python, how it is used in itom.