Avoid the artifact steps for integration tests

Integration tests produce none and trying to do these things breaks.

.circleci/config.yml

@@ -71,6 +71,8 @@ jobs:
       TAHOE_LAFS_TOX_ENVIRONMENT: "coverage"
       # Additional arguments to pass to tox.
       TAHOE_LAFS_TOX_ARGS: ""
+      # The path in which test artifacts will be placed.
+      ARTIFACTS_OUTPUT_PATH: "/tmp/artifacts"
       # Convince all of our pip invocations to look at the cached wheelhouse
       # we maintain.
       WHEELHOUSE_PATH: &WHEELHOUSE_PATH "/tmp/wheelhouse"
@@ -152,7 +154,7 @@ jobs:
           working_directory: "/tmp"
           command: |
             /tmp/project/.circleci/run-tests.sh \
-                /tmp/artifacts \
+                "${ARTIFACTS_OUTPUT_PATH}" \
                 "${TAHOE_LAFS_TOX_ENVIRONMENT}" \
                 "${TAHOE_LAFS_TOX_ARGS}"
           # trial output gets directed straight to a log.  avoid the circleci
@@ -212,6 +214,9 @@ jobs:
       <<: *UTF_8_ENVIRONMENT
       # Select the integration tests tox environments.
       TAHOE_LAFS_TOX_ENVIRONMENT: "integration"
+      # Disable artifact collection because py.test can't produce any.
+      ARTIFACTS_OUTPUT_PATH: ""
+
 
     steps:
       # DRY, YAML-style.  See the debian-9 steps.

.circleci/run-tests.sh

@@ -9,14 +9,20 @@ shift
 TAHOE_LAFS_TOX_ARGS=$1
 shift || :
 
-# Make sure we can actually write things to this directory.
-sudo --user nobody mkdir -p "${ARTIFACTS}"
+if [ -n "${ARTIFACTS}" ]; then
+    # If given an artifacts path, prepare to have some artifacts created
+    # there.  The integration tests don't produce any artifacts; that is the
+    # case where we expect not to end up here.
 
-SUBUNIT2="${ARTIFACTS}"/results.subunit2
+    # Make sure we can actually write things to this directory.
+    sudo --user nobody mkdir -p "${ARTIFACTS}"
 
-# Use an intermediate directory here because CircleCI extracts some label
-# information from its name.
-JUNITXML="${ARTIFACTS}"/junit/unittests/results.xml
+    SUBUNIT2="${ARTIFACTS}"/results.subunit2
+
+    # Use an intermediate directory here because CircleCI extracts some label
+    # information from its name.
+    JUNITXML="${ARTIFACTS}"/junit/unittests/results.xml
+fi
 
 # Run the test suite as a non-root user.  This is the expected usage some
 # small areas of the test suite assume non-root privileges (such as unreadable
@@ -40,6 +46,8 @@ sudo \
     -e "${TAHOE_LAFS_TOX_ENVIRONMENT}" \
     ${TAHOE_LAFS_TOX_ARGS}
 
-# Create a junitxml results area.
-mkdir -p "$(dirname "${JUNITXML}")"
-/tmp/tests/bin/subunit2junitxml < "${SUBUNIT2}" > "${JUNITXML}"
+if [ -n "${ARTIFACTS}" ]; then
+    # Create a junitxml results area.
+    mkdir -p "$(dirname "${JUNITXML}")"
+    /tmp/tests/bin/subunit2junitxml < "${SUBUNIT2}" > "${JUNITXML}"
+fi