Bug#950860: sfepy fails build2 autopkg test with python 3.8

[Matthias Klose]

Package: src:sfepy
Version: 2019.4-2
Severity: important
Tags: sid bullseye
User: debian-python at lists.debian.org
Usertags: python3.8

sfepy fails build2 autopkg test with python 3.8. Also the build2 *loops* over
py3versions -d, just the default version.

[...]
autopkgtest [23:30:01]: test build2: [-----------------------
run: python3.8
QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to '/tmp/runtime-ubuntu'
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/sfepy/postprocess/viewer.py", line 10, in
<module>
    from enthought.traits.api \
ModuleNotFoundError: No module named 'enthought'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "linear_elastic_interactive.py", line 18, in <module>
    from sfepy.postprocess.viewer import Viewer
  File "/usr/lib/python3/dist-packages/sfepy/postprocess/viewer.py", line 27, in
<module>
    from tvtk.pyface.scene_editor import SceneEditor
  File "/usr/lib/python3/dist-packages/tvtk/pyface/scene_editor.py", line 12, in
<module>
    SceneEditor = toolkit_object('scene_editor:SceneEditor')
  File "/usr/lib/python3/dist-packages/pyface/base_toolkit.py", line 144, in
__call__
    module = import_module(mname, package)
  File "/usr/lib/python3.8/importlib/__init__.py", line 127, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "/usr/lib/python3/dist-packages/tvtk/pyface/ui/qt4/scene_editor.py", line
19, in <module>
    from .decorated_scene import DecoratedScene
  File "/usr/lib/python3/dist-packages/tvtk/pyface/ui/qt4/decorated_scene.py",
line 19, in <module>
    from tvtk.api import tvtk
  File "/usr/lib/python3/dist-packages/tvtk/api.py", line 10, in <module>
    from tvtk.tvtk_access import tvtk
  File "/usr/lib/python3/dist-packages/tvtk/tvtk_access.py", line 34, in <module>
    from tvtk.tvtk_classes.vtk_version import vtk_build_version
  File "<frozen importlib._bootstrap>", line 991, in _find_and_load
  File "<frozen importlib._bootstrap>", line 971, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 914, in _find_spec
  File "<frozen importlib._bootstrap_external>", line 1342, in find_spec
  File "<frozen importlib._bootstrap_external>", line 1316, in _get_spec
  File "<frozen importlib._bootstrap_external>", line 1297, in _legacy_get_spec
  File "<frozen importlib._bootstrap>", line 414, in spec_from_loader
  File "<frozen importlib._bootstrap_external>", line 649, in
spec_from_file_location
  File "<frozen zipimport>", line 191, in get_filename
  File "<frozen zipimport>", line 711, in _get_module_code
  File "<frozen zipimport>", line 611, in _unmarshal_code
NameError: name '_boostrap_external' is not defined