ImportError: cannot import name 'soft_unicode' from 'markupsafe'

FYI: seen at BioHackathon with @proccaserra

erwan@computer:~/Code/plant-brapi-to-isa$ sudo docker run -it -v /home/erwan/Code/plant-brapi-to-isa/outputdir:/outputdir brapi2isa -t aHR0cHM6Ly9kb2kub3JnLzEwLjE1NDU0L0lBU1NUTg%3D%3D -e https://urgi.versailles.inra.fr/faidare/brapi/v1/
[sudo] password for erwan: 
Traceback (most recent call last):
  File "/brapi_to_isa.py", line 12, in <module>
    from isatools.convert import isatab2json
  File "/usr/local/lib/python3.7/site-packages/isatools/__init__.py", line 20, in <module>
    from isatools.convert import (
  File "/usr/local/lib/python3.7/site-packages/isatools/convert/isatab2sra.py", line 9, in <module>
    from isatools.convert import isatab2json, json2sra
  File "/usr/local/lib/python3.7/site-packages/isatools/convert/json2sra.py", line 5, in <module>
    from isatools import isajson, sra
  File "/usr/local/lib/python3.7/site-packages/isatools/sra.py", line 17, in <module>
    import jinja2
  File "/usr/local/lib/python3.7/site-packages/jinja2/__init__.py", line 12, in <module>
    from .environment import Environment
  File "/usr/local/lib/python3.7/site-packages/jinja2/environment.py", line 25, in <module>
    from .defaults import BLOCK_END_STRING
  File "/usr/local/lib/python3.7/site-packages/jinja2/defaults.py", line 3, in <module>
    from .filters import FILTERS as DEFAULT_FILTERS  # noqa: F401
  File "/usr/local/lib/python3.7/site-packages/jinja2/filters.py", line 13, in <module>
    from markupsafe import soft_unicode
ImportError: cannot import name 'soft_unicode' from 'markupsafe' (/usr/local/lib/python3.7/site-packages/markupsafe/__init__.py)

The traceback starts in brapi_to_isa.py, reaches isatools/sra.py, and fails while importing Jinja2 and MarkupSafe. Reproduce it with the shown Docker command and inspect the image's Python dependency metadata. Done means the container starts without this ImportError and the invocation proceeds further.