/usr/share/pyshared/zope/testrunner/testrunner-subunit-err.txt is in python-zope.testrunner 4.0.3-3.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 | Using subunit output without subunit installed
==============================================
To use the --subunit reporting option, you must have subunit installed. If you
do not, you will get an error message:
    >>> import os.path, sys
    >>> directory_with_tests = os.path.join(this_directory, 'testrunner-ex')
    >>> defaults = [
    ...     '--path', directory_with_tests,
    ...     '--tests-pattern', '^sampletestsf?$',
    ...     ]
    >>> from zope import testrunner
    >>> sys.argv = 'test --subunit'.split()
    >>> _ = testrunner.run_internal(defaults)
            Subunit is not installed. Please install Subunit
            to generate subunit output.
    <BLANKLINE>
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