example failing ouput fixed by https://github.com/pantsbuild/pants/pull/7695 (reproducible if 3rdparty/python/BUILD is edited to have prepend_to_pythonpath=False).

gistfile1.txt

> ./pants test examples/tests/python/example_test/pkg_resources_access -- -vs
20:45:00 00:00 [main]
               (To run a reporting server: ./pants server)
20:45:02 00:02   [setup]
20:45:22 00:22     [parse]
               Executing tasks in goals: bootstrap -> imports -> unpack-wheels -> unpack-jars -> deferred-sources -> native-compile -> link -> jvm-platform-validate -> gen -> resolve -> resources -> compile -> pyprep -> test
20:45:23 00:23   [bootstrap]
20:45:23 00:23     [substitute-aliased-targets]
20:45:23 00:23     [jar-dependency-management]
20:45:23 00:23     [bootstrap-jvm-tools]
20:45:23 00:23     [provide-tools-jar]
20:45:23 00:23   [imports]
20:45:23 00:23     [ivy-imports]
20:45:23 00:23   [unpack-wheels]
20:45:23 00:23     [unpack-wheels]
20:45:23 00:23   [unpack-jars]
20:45:23 00:23     [unpack-jars]
20:45:24 00:24   [deferred-sources]
20:45:24 00:24     [deferred-sources]
20:45:24 00:24   [native-compile]
20:45:24 00:24     [conan-prep]
20:45:24 00:24     [conan-fetch]
20:45:24 00:24     [c-for-ctypes]
20:45:24 00:24     [cpp-for-ctypes]
20:45:24 00:24   [link]
20:45:24 00:24     [shared-libraries]
20:45:24 00:24   [jvm-platform-validate]
20:45:24 00:24     [jvm-platform-validate]
20:45:24 00:24   [gen]
20:45:24 00:24     [antlr-java]
20:45:24 00:24     [antlr-py]
20:45:24 00:24     [jaxb]
20:45:24 00:24     [protoc]
20:45:24 00:24     [ragel]
20:45:24 00:24     [thrift-java]
20:45:24 00:24     [thrift-py]
20:45:24 00:24     [py-thrift-namespace-clash-check]
20:45:24 00:24     [grpcio-prep]
20:45:24 00:24     [grpcio-run]
20:45:24 00:24     [wire]
20:45:24 00:24     [avro-java]
20:45:24 00:24     [go-thrift]
20:45:24 00:24     [go-protobuf]
20:45:24 00:24     [jax-ws]
20:45:24 00:24     [scrooge]
20:45:24 00:24     [thrifty]
20:45:24 00:24   [resolve]
20:45:24 00:24     [ivy]
20:45:24 00:24     [coursier]
20:45:24 00:24     [go]
20:45:24 00:24     [scala-js-compile]
20:45:24 00:24     [scala-js-link]
20:45:24 00:24     [node]
20:45:24 00:24   [resources]
20:45:24 00:24     [prepare]
20:45:24 00:24     [services]
20:45:24 00:24   [compile]
20:45:24 00:24     [node]
20:45:24 00:24     [compile-jvm-prep-command]
20:45:24 00:24       [jvm_prep_command]
20:45:24 00:24     [compile-prep-command]
20:45:24 00:24     [compile]
20:45:24 00:24     [rsc]
20:45:24 00:24     [zinc]
20:45:24 00:24     [javac]
20:45:24 00:24     [cpp]
20:45:24 00:24     [errorprone]
20:45:24 00:24     [findbugs]
20:45:24 00:24     [go]
20:45:24 00:24   [pyprep]
20:45:24 00:24     [interpreter]
20:45:25 00:25     [build-local-dists]
20:45:25 00:25     [requirements]
                   Invalidated 36 targets.
20:45:34 00:34     [sources]
                   Invalidated 7 targets.
20:45:36 00:36   [test]
20:45:36 00:36     [test-jvm-prep-command]
20:45:36 00:36       [jvm_prep_command]
20:45:36 00:36     [test-prep-command]
20:45:36 00:36     [legacy]
20:45:36 00:36     [pytest-prep]
                   Invalidated 67 targets.
20:45:37 00:37     [pytest]
                   Invalidated 1 target.
                   scrubbed PYTHONPATH=/Users/dmcclanahan/tools/pants/src/python: from py.test environment
20:45:37 00:37       [run]
                     ============== test session starts ===============
                     platform darwin -- Python 3.6.4, pytest-3.6.4, py-1.8.0, pluggy-0.7.1 -- /Users/dmcclanahan/tools/pants/build-support/pants_dev_deps.py36.venv/bin/python3
                     cachedir: .pants.d/.pytest_cache
                     rootdir: /Users/dmcclanahan/tools/pants/.pants.d, inifile: /Users/dmcclanahan/tools/pants/.pants.d/test/pytest-prep/CPython-3.6.4/17ddcc03ac48d31e9cf1302852e6560f1c1e986b/pytest.ini
                     plugins: timeout-1.2.1, cov-2.4.0
                     collecting ... collected 0 items / 1 errors

                     ===================== ERRORS =====================
                     _ ERROR collecting pyprep/sources/a37893c446f1421d0d8c6bfee30dbb8398f9e9bf/example_test/pkg_resources_access/test_bigquery_python_run.py _
                     .pants.d/pyprep/sources/a37893c446f1421d0d8c6bfee30dbb8398f9e9bf/example_test/pkg_resources_access/test_bigquery_python_run.py:7: in <module>
                         from google.cloud import bigquery
                     .pants.d/pyprep/requirements/CPython-3.6.4/d2bd9c3099b3a4915da2a2607598fbf04ac0577a/.deps/google_cloud_bigquery-1.10.0-py2.py3-none-any.whl/google/cloud/bigquery/__init__.py:33: in <module>
                         __version__ = get_distribution("google-cloud-bigquery").version
                     .pants.d/test/pytest-prep/CPython-3.6.4/7fda01ac0dc18485583dd843fa7be44f333e70b5/.deps/setuptools-40.6.3-py2.py3-none-any.whl/pkg_resources/__init__.py:479: in get_distribution
                         dist = get_provider(dist)
                     .pants.d/test/pytest-prep/CPython-3.6.4/7fda01ac0dc18485583dd843fa7be44f333e70b5/.deps/setuptools-40.6.3-py2.py3-none-any.whl/pkg_resources/__init__.py:355: in get_provider
                         return working_set.find(moduleOrReq) or require(str(moduleOrReq))[0]
                     .pants.d/test/pytest-prep/CPython-3.6.4/7fda01ac0dc18485583dd843fa7be44f333e70b5/.deps/setuptools-40.6.3-py2.py3-none-any.whl/pkg_resources/__init__.py:898: in require
                         needed = self.resolve(parse_requirements(requirements))
                     .pants.d/test/pytest-prep/CPython-3.6.4/7fda01ac0dc18485583dd843fa7be44f333e70b5/.deps/setuptools-40.6.3-py2.py3-none-any.whl/pkg_resources/__init__.py:784: in resolve
                         raise DistributionNotFound(req, requirers)
                     E   pkg_resources.DistributionNotFound: The 'google-cloud-bigquery' distribution was not found and is required by the application
                     - generated xml file: /Users/dmcclanahan/tools/pants/.pants.d/test/pytest/examples.tests.python.example_test.pkg_resources_access.pkg_resources_access/junitxml/TEST-examples.tests.python.example_test.pkg_resources_access.pkg_resources_access.xml -
                     ============ 1 error in 0.25 seconds =============

                   examples/tests/python/example_test/pkg_resources_access                         .....   FAILURE
FAILURE: FAILURE


               Waiting for background workers to finish.
20:45:39 00:39   [complete]
               FAILURE