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.