Only upload coverage measurement if we took one

.circleci/config.yml

@@ -154,6 +154,8 @@ jobs:
       # we maintain.
       WHEELHOUSE_PATH: &WHEELHOUSE_PATH "/tmp/wheelhouse"
       PIP_FIND_LINKS: "file:///tmp/wheelhouse"
+      # Upload the coverage report.
+      UPLOAD_COVERAGE: "yes"
 
     # pip cannot install packages if the working directory is not readable.
     # We want to run a lot of steps as nobody instead of as root.
@@ -202,7 +204,7 @@ jobs:
       - run: &SUBMIT_COVERAGE
           name: "Submit coverage results"
           command: |
-            /tmp/venv/bin/codecov
+            [ -n "${UPLOAD_COVERAGE}" ] && /tmp/venv/bin/codecov
 
 
   debian-8:
@@ -250,6 +252,8 @@ jobs:
       TAHOE_LAFS_TOX_ENVIRONMENT: "deprecations,upcoming-deprecations"
       # Put the logs somewhere we can report them.
       TAHOE_LAFS_WARNINGS_LOG: "/tmp/artifacts/deprecation-warnings.log"
+      # The deprecations tox environments don't do coverage measurement.
+      UPLOAD_COVERAGE: ""
 
 
   integration: