E.g.:

{"action": "test_groups", "line": 34, "groups": ["testing/marionette/harness/marionette_harness/tests/unit-tests.ini"]}
{"status": "ERROR", "group": "", "line": 1734, "subtest": null, "action": "test_result", "test": "testing/marionette/harness/marionette_harness/tests/unit/test_crash.py TestCrashInTearDown.test_crash_in_teardown", "message": "AssertionError: \"Process crashed\" does not match \"Process killed because the connection to Marionette server is lost. Check gecko.log for errors (Reason: Connection timed out after 10s)\"", "stack": "Traceback (most recent call last):\n  File \"Z:\\task_1587179517\\build\\venv\\lib\\site-packages\\marionette_harness\\marionette_test\\testcases.py\", line 190, in run\n    self.tearDown()\n  File \"Z:\\task_1587179517\\build\\tests\\marionette\\tests\\testing\\marionette\\harness\\marionette_harness\\tests\\unit\\test_crash.py\", line 193, in tearDown\n    self.crash, parent=True)\n", "expected": "PASS"}