It was hard for me to handle this. It turns out that the subunit has a new version 2 of this protocol and what the subunit2junitxml version expected. See https://pypi.python.org/pypi/python-subunit
subunit-1to2 , subunit2junitxml. , , , - :
trial --reporter=subunit <mypackage> | subunit-1to2 | subunit2junitxml --no-passthrough --output-to=$WORKSPACE/temp/output.xml
, -.