python-nb2plots fails to build with Python 3.9.0a5.

jupyter nbconvert --to html example_notebook.ipynb --stdout > \
	_build/html/example_notebook.html
Traceback (most recent call last):
  File "/usr/bin/jupyter-nbconvert", line 11, in <module>
    load_entry_point('nbconvert==5.6.0', 'console_scripts', 'jupyter-nbconvert')()
  File "/usr/lib/python3.9/site-packages/pkg_resources/__init__.py", line 490, in load_entry_point
    return get_distribution(dist).load_entry_point(group, name)
  File "/usr/lib/python3.9/site-packages/pkg_resources/__init__.py", line 2855, in load_entry_point
    return ep.load()
  File "/usr/lib/python3.9/site-packages/pkg_resources/__init__.py", line 2446, in load
    return self.resolve()
  File "/usr/lib/python3.9/site-packages/pkg_resources/__init__.py", line 2452, in resolve
    module = __import__(self.module_name, fromlist=['__name__'], level=0)
  File "/usr/lib/python3.9/site-packages/nbconvert/__init__.py", line 4, in <module>
    from .exporters import *
  File "/usr/lib/python3.9/site-packages/nbconvert/exporters/__init__.py", line 3, in <module>
    from .html import HTMLExporter
  File "/usr/lib/python3.9/site-packages/nbconvert/exporters/html.py", line 14, in <module>
    from nbconvert.filters.highlight import Highlight2HTML
  File "/usr/lib/python3.9/site-packages/nbconvert/filters/__init__.py", line 7, in <module>
    from .strings import *
  File "/usr/lib/python3.9/site-packages/nbconvert/filters/strings.py", line 22, in <module>
    from defusedxml import cElementTree as ElementTree
  File "/usr/lib/python3.9/site-packages/defusedxml/cElementTree.py", line 10, in <module>
    from xml.etree.cElementTree import TreeBuilder as _TreeBuilder
ModuleNotFoundError: No module named 'xml.etree.cElementTree'

See https://docs.python.org/3.9/whatsnew/3.9.html#removed

"The xml.etree.cElementTree module has been removed."

See also defusedxml bug bz1817700.

nbconvert is yet to be processed.


For the build logs, see:
https://copr-be.cloud.fedoraproject.org/results/@python/python3.9/fedora-rawhide-x86_64/01321095-python-nb2plots/

For all our attempts to build python-nb2plots with Python 3.9, see:
https://copr.fedorainfracloud.org/coprs/g/python/python3.9/package/python-nb2plots/

Testing and mass rebuild of packages is happening in copr. You can follow these instructions to test locally in mock if your package builds with Python 3.9:
https://copr.fedorainfracloud.org/coprs/g/python/python3.9/

Let us know here if you have any questions.

Python 3.9 will be included in Fedora 33. To make that update smoother, we're building Fedora packages with early pre-releases of Python 3.9.
A build failure prevents us from testing all dependent packages (transitive [Build]Requires), so if this package is required a lot, it's important for us to get it fixed soon.
We'd appreciate help from the people who know this package best, but if you don't want to work on this now, let us know so we can try to work around it on our side.