11:25:13 00:06     [pytest-prep]
                   Invalidated 3 targets.
11:25:14 00:07     [pytest]
                   Invalidated 1 target.
                   scrubbed PYTHONPATH=/Users/clivingston/workspace/pants/src/python: from py.test environment
11:25:14 00:07       [run]
                     Failed to find compatible interpreter for constraints: [u'CPython>=3.6,<4', u'CPython>=2.7,<3']

                   tests/python/pants_test/backend/python:interpreter_cache                        .....   NOT RUN
FAILURE


               Waiting for background workers to finish.
11:25:14 00:07   [complete]
               FAILURE