Bug#972194: pyside2 is not ready for python3.9

[Matthias Klose <doko@debian.org>]

Package: src:pyside2
Version: 5.15.0-3
Severity: serious
Tags: sid bullseye
User: debian-python@lists.debian.org
Usertags: python3.9

pyside2 is not ready for python3.9:

[...]
dpkg-buildpackage: info: host architecture amd64
dpkg-source: info: using options from pyside2-5.15.0/debian/source/options:
--extend-diff-ignore=^[^/]*[.]egg-info/
 debian/rules clean
dh clean --with python3,sphinxdoc --buildsystem=pybuild
   dh_auto_clean -O--buildsystem=pybuild
I: pybuild base:217: python3.9 setup.py clean
Unsupported python version detected. Only these python versions are supported:
[(2, 7), (3, 5), (3, 6), (3, 7), (3, 8)]
E: pybuild pybuild:352: clean: plugin distutils failed with: exit code=1:
python3.9 setup.py clean
dh_auto_clean: error: pybuild --clean -i python{version} -p "3.9 3.8" returned
exit code 13
make: *** [debian/rules:30: clean] Error 25