any ideas on this? its as if docopt in my code is conflicting with pytest-cov.

pants_version: 1.23.0

d248ba4f9860a2fdc5/.deps/boto3-1.11.3-py2.py3-none-any.whl
                     pex:     /home/ruthgracewong/python-commons/.pants.d/pyprep/requirements/CPython-3.6.8/285ef0aeec651f37c5dfe3d248ba4f9860a2fdc5/.deps/chardet-3.0.4-py2.py3-none-any.whl
                     pex:     /home/ruthgracewong/python-commons/.pants.d/pyprep/requirements/CPython-3.6.8/285ef0aeec651f37c5dfe3d248ba4f9860a2fdc5/.deps/idna-2.8-py2.py3-none-any.whl
                     pex:     /home/ruthgracewong/python-commons/.pants.d/pyprep/sources/046be5bc3b0575f4d1acc33b48dbdd2eca5d778d/.deps/setuptools-40.6.3-py2.py3-none-any.whl
                     pex:     /home/ruthgracewong/python-commons/.pants.d/test/pytest-prep/CPython-3.6.8/6b63dbeb8f04af2fc6ba79516c3440a6735643d3/.bootstrap
                     pex:   * - paths that do not exist or will be imported via zipimport
                     collected 0 items / 1 errors

                     ===================== ERRORS =====================
                     _ ERROR collecting .pants.d/pyprep/sources/046be5bc3b0575f4d1acc33b48dbdd2eca5d778d/pinterest/container_report/test_container_report.py _
                     .pants.d/pyprep/sources/046be5bc3b0575f4d1acc33b48dbdd2eca5d778d/pinterest/container_report/test_container_report.py:3: in <module>
                         import pinterest.container_report.container_report
                     .pants.d/pyprep/sources/046be5bc3b0575f4d1acc33b48dbdd2eca5d778d/pinterest/container_report/container_report.py:38: in <module>
                         arguments = docopt(__doc__, version=VERSION)
                     .pants.d/pyprep/requirements/CPython-3.6.8/285ef0aeec651f37c5dfe3d248ba4f9860a2fdc5/.deps/docopt-0.6.2-py2.py3-none-any.whl/docopt.py:567: in docopt
                         options_first)
                     .pants.d/pyprep/requirements/CPython-3.6.8/285ef0aeec651f37c5dfe3d248ba4f9860a2fdc5/.deps/docopt-0.6.2-py2.py3-none-any.whl/docopt.py:444: in parse_argv
                         parsed += parse_long(tokens, options)
                     .pants.d/pyprep/requirements/CPython-3.6.8/285ef0aeec651f37c5dfe3d248ba4f9860a2fdc5/.deps/docopt-0.6.2-py2.py3-none-any.whl/docopt.py:312: in parse_long
                         (long, ', '.join(o.long for o in similar)))
                     E   docopt.DocoptExit: --cov is not a unique prefix: --cov-report, --cov-config?
                     E   Usage:
                     E     container_report.py [-c] FILENAME [-o OUTPUT_FILENAME]