vit fails to build. This also happens with Python 3.9.0a6, but not only.

+ /usr/bin/python3 -m unittest
EE
======================================================================
ERROR: test.test_list_batcher (unittest.loader._FailedTest)
----------------------------------------------------------------------
ImportError: Failed to import test module: test.test_list_batcher
Traceback (most recent call last):
  File "/usr/lib64/python3.9/unittest/loader.py", line 436, in _find_test_path
    module = self._get_module_from_name(name)
  File "/usr/lib64/python3.9/unittest/loader.py", line 377, in _get_module_from_name
    __import__(name)
  File "/builddir/build/BUILD/vit-2.0.0/test/test_list_batcher.py", line 4, in <module>
    from vit.list_batcher import ListBatcher
  File "/builddir/build/BUILD/vit-2.0.0/vit/__init__.py", line 2, in <module>
    from .application import Application
  File "/builddir/build/BUILD/vit-2.0.0/vit/application.py", line 13, in <module>
    import urwid
  File "/usr/lib64/python3.9/site-packages/urwid/__init__.py", line 25, in <module>
    from urwid.widget import (FLOW, BOX, FIXED, LEFT, RIGHT, CENTER, TOP, MIDDLE,
  File "/usr/lib64/python3.9/site-packages/urwid/widget.py", line 26, in <module>
    from urwid.util import (MetaSuper, decompose_tagmarkup, calc_width,
  File "/usr/lib64/python3.9/site-packages/urwid/util.py", line 60, in <module>
    detected_encoding = detect_encoding()
  File "/usr/lib64/python3.9/site-packages/urwid/util.py", line 57, in detect_encoding
    locale.setlocale(locale.LC_ALL, initial)
  File "/usr/lib64/python3.9/locale.py", line 610, in setlocale
    return _setlocale(category, locale)
locale.Error: unsupported locale setting


======================================================================
ERROR: vit (unittest.loader._FailedTest)
----------------------------------------------------------------------
ImportError: Failed to import test module: vit
Traceback (most recent call last):
  File "/usr/lib64/python3.9/unittest/loader.py", line 470, in _find_test_path
    package = self._get_module_from_name(name)
  File "/usr/lib64/python3.9/unittest/loader.py", line 377, in _get_module_from_name
    __import__(name)
  File "/builddir/build/BUILD/vit-2.0.0/vit/__init__.py", line 2, in <module>
    from .application import Application
  File "/builddir/build/BUILD/vit-2.0.0/vit/application.py", line 13, in <module>
    import urwid
  File "/usr/lib64/python3.9/site-packages/urwid/__init__.py", line 25, in <module>
    from urwid.widget import (FLOW, BOX, FIXED, LEFT, RIGHT, CENTER, TOP, MIDDLE,
  File "/usr/lib64/python3.9/site-packages/urwid/widget.py", line 26, in <module>
    from urwid.util import (MetaSuper, decompose_tagmarkup, calc_width,
  File "/usr/lib64/python3.9/site-packages/urwid/util.py", line 60, in <module>
    detected_encoding = detect_encoding()
  File "/usr/lib64/python3.9/site-packages/urwid/util.py", line 57, in detect_encoding
    locale.setlocale(locale.LC_ALL, initial)
  File "/usr/lib64/python3.9/locale.py", line 610, in setlocale
    return _setlocale(category, locale)
locale.Error: unsupported locale setting


----------------------------------------------------------------------
Ran 2 tests in 0.000s

FAILED (errors=2)

See also https://koschei.fedoraproject.org/package/vit


For the build logs with Python 3.9, see:
https://copr-be.cloud.fedoraproject.org/results/@python/python3.9/fedora-rawhide-x86_64/01365688-vit/

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

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.