Filed by: csabou [at] mozilla.com

https://treeherder.mozilla.org/logviewer.html#?job_id=221140687&repo=autoland

https://queue.taskcluster.net/v1/task/Yh2DgqK_Qxe2g9jF5a3_6g/runs/0/artifacts/public/logs/live_backing.log

11:04:16 WARNING - Failed to gather test failure debug: Browsing context has been discarded
11:04:16 WARNING - stacktrace:
11:04:16 WARNING - WebDriverError@chrome://marionette/content/error.js:179:5
11:04:16 WARNING - NoSuchWindowError@chrome://marionette/content/error.js:411:5
11:04:16 WARNING - assert.that/<@chrome://marionette/content/assert.js:418:13
11:04:16 WARNING - assert.open@chrome://marionette/content/assert.js:174:10
11:04:16 WARNING - GeckoDriver.prototype.takeScreenshot@chrome://marionette/content/driver.js:2927:13
11:04:16 WARNING - despatch@chrome://marionette/content/server.js:290:20
11:04:16 WARNING - asyncexecute@chrome://marionette/content/server.js:263:11
11:04:16 WARNING - asynconPacket/<@chrome://marionette/content/server.js:236:15
11:04:16 WARNING - async*onPacket@chrome://marionette/content/server.js:235:8
11:04:16 WARNING - _onJSONObjectReady/<@chrome://marionette/content/transport.js:493:9
11:04:16 WARNING -
11:04:16 INFO - TEST-UNEXPECTED-FAIL | testing/marionette/harness/marionette_harness/tests/unit/test_reftest.py TestReftest.test_url_comparison | AssertionError: u'PASS' != u'TIMEOUT'
11:04:16 INFO - - PASS
11:04:16 INFO - + TIMEOUT
11:04:16 INFO - Traceback (most recent call last):
11:04:16 INFO - File "/Users/cltbld/tasks/task_1547145883/build/venv/lib/python2.7/site-packages/marionette_harness/marionette_test/testcases.py", line 159, in run
11:04:16 INFO - testMethod()
11:04:16 INFO - File "/Users/cltbld/tasks/task_1547145883/build/tests/marionette/tests/testing/marionette/harness/marionette_harness/tests/unit/test_reftest.py", line 60, in test_url_comparison
11:04:16 INFO - self.assertEqual(u"PASS", rv[u"value"][u"status"])
11:04:16 INFO - TEST-INFO took 10195ms
11:04:16 INFO - 1547147056943 Marionette DEBUG 8 -> [0,18,"reftest:teardown",{}]
11:04:16 INFO - 1547147056944 Marionette DEBUG 8 <- [1,18,{"error":"unsupported operation","message":"Called reftest:teardown before reftest:start","stacktrace":"WebDriverError@ ... et@chrome://marionette/content/server.js:235:8\n_onJSONObjectReady/<@chrome://marionette/content/transport.js:493:9\n"},null]
11:04:16 INFO - 1547147056947 Marionette DEBUG 8 -> [0,19,"WebDriver:SwitchToWindow",{"focus":true,"name":"2147483649"}]
11:04:16 INFO - 1547147056950 Marionette DEBUG 8 <- [1,19,null,{"value":null}]
11:04:16 INFO - 1547147056953 Marionette DEBUG 8 -> [0,20,"Marionette:SetContext",{"value":"content"}]
11:04:16 INFO - 1547147056955 Marionette DEBUG 8 <- [1,20,null,{"value":null}]
11:04:16 INFO - 1547147056957 Marionette DEBUG 8 -> [0,21,"Marionette:GetContext",{}]
11:04:16 INFO - 1547147056958 Marionette DEBUG 8 <- [1,21,null,{"value":"content"}]
11:04:16 INFO - 1547147056961 Marionette DEBUG 8 -> [0,22,"Marionette:SetContext",{"value":"chrome"}]
11:04:16 INFO - 1547147056963 Marionette DEBUG 8 <- [1,22,null,{"value":null}]
11:04:16 INFO - --DOMWINDOW == 4 (0x127bbb400) [pid = 1061] [serial = 4] [outer = 0x0] [url = http://127.0.0.1:50464/test.html]
11:04:16 INFO - --DOMWINDOW == 3 (0x116fe5c00) [pid = 1061] [serial = 3] [outer = 0x0] [url = about:blank]
11:04:16 INFO - --DOMWINDOW == 2 (0x11dff1400) [pid = 1061] [serial = 2] [outer = 0x0] [url = about:blank]
11:04:16 INFO - 1547147056973 Marionette DEBUG 8 -> [0,23,"WebDriver:ExecuteScript",{"script":"Components.utils.import("resource://gre/modules/Preferences.jsm");\n ... ontent"],"filename":"../../venv/lib/python2.7/site-packages/marionette_driver/marionette.py","sandbox":"default","line":870}]
11:04:16 INFO - 1547147056982 Marionette DEBUG 8 <- [1,23,null,{"value":null}]
11:04:16 INFO - 1547147056984 Marionette DEBUG 8 -> [0,24,"Marionette:SetContext",{"value":"content"}]
11:04:16 INFO - 1547147056986 Marionette DEBUG 8 <- [1,24,null,{"value":null}]
11:04:16 INFO - 1547147056989 Marionette DEBUG 8 -> [0,25,"WebDriver:DeleteSession",{}]
11:04:17 INFO - 1547147056994 Marionette DEBUG 8 <- [1,25,null,{"value":null}]
11:04:17 INFO - 1547147056997 Marionette DEBUG Closed connection 8

This started after this push here: https://treeherder.mozilla.org/#/jobs?repo=autoland&resultStatus=success%2Ctestfailed%2Cbusted%2Cexception&classifiedState=unclassified&revision=daf05866f9ddcd5a362b4d436477f3e01abd4234&searchStr=mn&selectedJob=221132110

Also these failures: https://treeherder.mozilla.org/logviewer.html#/jobs?job_id=221137313&repo=autoland&lineNumber=60619

Geoffrey, care to take a look at these? Thank you.

Decided to backout due to failure rate: https://hg.mozilla.org/integration/autoland/rev/3994da3447c34fbf333b51776fd91afeb7fa1dbf

You actually fixed it with the backout.