Error on run: ImportError: cannot import name 'soft_unicode' from 'markupsafe'

MFiX Bug report
#1

Sharing a problem with a solution:
Version: 21.1.1 Built from tar.gz with pip
Python 3.9.7

When I would try to run a built solver, I would see this error (at the end of a long traceback)

ImportError: cannot import name ‘soft_unicode’ from ‘markupsafe’

This appears to be due to markupsafe removing or renaming soft_unicode. They recommend use of soft_str
https://markupsafe.palletsprojects.com/en/2.1.x/changes/#version-2-1-0

It can be solved by rolling back your markupsafe to version 2.0.1, which still includes this class/function. You can do so by using this command:
pip install markupsafe==2.0.1

#2

Note: I think this is something for flask → jinja2 to catch up with and not an mfix source problem.

#3

Thanks. We are not even using all the dependencies that Flask pulls in.