Use BASH_ENV to avoid duplication of job steps

.circleci/config.yml

@@ -291,33 +291,18 @@ jobs:
       - "checkout"
       - run: *SETUP_VIRTUALENV
       - run:
-          name: "Run test suite (python3.6)"
+          name: "Limit Modules"
           command: |
 
-            # Constrain the modules exercised under Python 3 based on the list
-            # we keep in _python3. Exporting inside a command seems to be the
-            # preferred way of setting an environment variable (or otherwise
-            # constraining the test run) dynamically:
+            # Limit the modules exercised under Python 3 dynamically, based
+            # on the list we keep in allmydata.util._python3. Use BASH_ENV to
+            # communicate this to the RUN_TESTS step:
             #
-            #   https://ideas.circleci.com/ideas/CCI-I-67
-            #
-            # This seems to force a choice between DRY code with an overloaded
-            # RUN_TESTS, or an uncluttered RUN_TESTS and code duplication here.
-            # Que sera, sera.
+            #   https://circleci.com/docs/2.0/env-vars/#using-parameters-and-bash-environment
 
-            export TAHOE_LAFS_TOX_ARGS="$(/tmp/tahoe-lafs.tox/${TAHOE_LAFS_TOX_ENVIRONMENT}/bin/python -c 'from allmydata.util._python3 import PORTED_TEST_MODULES; print(" ".join(PORTED_TEST_MODULES))')" \
-
-            /tmp/project/.circleci/run-tests.sh \
-                "/tmp/venv" \
-                "/tmp/project" \
-                "${ALLOWED_FAILURE}" \
-                "${ARTIFACTS_OUTPUT_PATH}" \
-                "${TAHOE_LAFS_TOX_ENVIRONMENT}" \
-                "${TAHOE_LAFS_TOX_ARGS}"
-          # trial output gets directed straight to a log.  avoid the circleci
-          # timeout while the test suite runs.
-          no_output_timeout: "20m"
+            echo "export TAHOE_LAFS_TOX_ARGS=\"$(/tmp/tahoe-lafs.tox/${TAHOE_LAFS_TOX_ENVIRONMENT}/bin/python -c 'from allmydata.util._python3 import PORTED_TEST_MODULES; print(" ".join(PORTED_TEST_MODULES))')\"" >> ${BASH_ENV}
 
+      - run: *RUN_TESTS
       - store_test_results: *STORE_TEST_RESULTS
       - store_artifacts: *STORE_TEST_LOG
       - store_artifacts: *STORE_OTHER_ARTIFACTS