Comment 0 for bug 1426340

To replicate:
add
import bogus_package_that_does_not_exist
to the start of content_json function in nailgun/nailgun/api/v1/handlers/base.py

Run the test which uses it, for example
./run_tests.sh -t nailgun/nailgun/test/integration/test_notification.py::TestNotification::test_notification_node_discover

You should get lot of HTML in your console instead of a traceback string.