OSError: [WinError 6] The handle is invalid (sys.stdout.write)

[pllim]

I don't run the test suite locally on Windows often and the Windows job in Actions does not see this error. While Actions use tox, locally I use conda env without tox to run the tests. I am seeing astropy/astropy#14791 that I do not know how to debug, so any idea would be greatly appreciated.

You could reproduce this error either from our RC or from dev version built from source. Example RC install:

pip install "astropy[test]==5.3rc1"

Then you can run a subset of the test suite that would give you these errors on Windows:

python -c "import astropy; astropy.test(package='io.votable')"

If I drop into an interactive Python session, I can still see this error when I run pytest like this:

>>> import astropy
>>> astropy.test(package="io.votable")

However, in the same session, there is no error if I run one of the failing test case on its own without pytest:

>>> from astropy.io.votable.tests.table_test import test_validate_output_invalid
>>> test_validate_output_invalid()

I could not run pytest from CLI like this because it is throwing ValueError: Plugin already registered: ...\astropy\conftest.py, which seems like an unrelated problem that I don't have time to dig into right now. But if you don't get the ValueError and you are able to build astropy from source, you can also do this locally from the source checkout directory:

pytest astropy/io/votable/tests/table_test.py

All the astropy.test() calls go through our test runner here:

https://github.com/astropy/astropy/blob/main/astropy/tests/runner.py

https://github.com/astropy/astropy/blob/eec06978bcf37dba7e998f198003a3b6cbfcfb94/astropy/__init__.py#L137