severity 938919 serious thanks python-zope.testrunner in testing depends on python-zope.exceptions which has already been dropped by the zope.exceptions source package.
This has been addressed in unstable by dropping the python-zope.testrunner binary package, however that fix cannot currently migrate to testing because /usr/bin/zope-testrunner was moved to the python3-zope.testrunner binary package but no breaks/replaces relationships were put in place.