Filed by: egao [at] mozilla.com
Parsed log: https://treeherder.mozilla.org/logviewer.html#?job_id=265783740&repo=try
Full log: https://queue.taskcluster.net/v1/task/Mwree0pGRcmi5th13MZXgw/runs/0/artifacts/public/logs/live_backing.log

Platform: debian 10
Suite: mochitest-e10s
Chunk: 1

Context:
[task 2019-09-09T20:42:42.545Z] 20:42:42 INFO - TEST-START | dom/html/test/test_fullscreen-api-race.html
[task 2019-09-09T20:42:42.684Z] 20:42:42 INFO - TEST-INFO | started process screentopng
[task 2019-09-09T20:42:42.847Z] 20:42:42 INFO - TEST-INFO | screentopng: exit 0
[task 2019-09-09T20:42:42.847Z] 20:42:42 INFO - Buffered messages logged at 20:42:42
[task 2019-09-09T20:42:42.847Z] 20:42:42 INFO - TEST-PASS | dom/html/test/test_fullscreen-api-race.html | A valid string reason is expected
[task 2019-09-09T20:42:42.848Z] 20:42:42 INFO - TEST-PASS | dom/html/test/test_fullscreen-api-race.html | Reason cannot be empty
[task 2019-09-09T20:42:42.850Z] 20:42:42 INFO - Testing openNewTab, navigate
[task 2019-09-09T20:42:42.851Z] 20:42:42 INFO - About to enter fullscreen
[task 2019-09-09T20:42:42.852Z] 20:42:42 INFO - TEST-PASS | dom/html/test/test_fullscreen-api-race.html | Should get fullscreenchange
[task 2019-09-09T20:42:42.853Z] 20:42:42 INFO - TEST-PASS | dom/html/test/test_fullscreen-api-race.html | Should have entered fullscreen
[task 2019-09-09T20:42:42.854Z] 20:42:42 INFO - Buffered messages finished
[task 2019-09-09T20:42:42.854Z] 20:42:42 INFO - TEST-UNEXPECTED-FAIL | dom/html/test/test_fullscreen-api-race.html | The window should be in fullscreen
[task 2019-09-09T20:42:42.854Z] 20:42:42 INFO - SimpleTest.ok@SimpleTest/SimpleTest.js:277:18
[task 2019-09-09T20:42:42.854Z] 20:42:42 INFO - listener@dom/html/test/test_fullscreen-api-race.html:137:11
[task 2019-09-09T20:42:42.854Z] 20:42:42 INFO - EventListener.handleEventrunTest/</<@dom/html/test/test_fullscreen-api-race.html:147:11
[task 2019-09-09T20:42:42.855Z] 20:42:42 INFO - runTest/<@dom/html/test/test_fullscreen-api-race.html:122:12
[task 2019-09-09T20:42:42.855Z] 20:42:42 INFO - promise callbackrunTest@dom/html/test/test_fullscreen-api-race.html:121:6
[task 2019-09-09T20:42:42.855Z] 20:42:42 INFO - next@dom/html/test/test_fullscreen-api-race.html:161:12
[task 2019-09-09T20:42:42.855Z] 20:42:42 INFO - Async*@dom/html/test/test_fullscreen-api-race.html:35:17
[task 2019-09-09T20:42:42.855Z] 20:42:42 INFO - rval@SimpleTest/SimpleTest.js:146:30
[task 2019-09-09T20:42:42.856Z] 20:42:42 INFO - About to navigate to another page
[task 2019-09-09T20:42:42.856Z] 20:42:42 INFO - GECKO(3026) | JavaScript error: chrome://browser/content/browser-fullScreenAndPointerLock.js, line 407: Error: TelemetryStopwatch: key "FULLSCREEN_CHANGE_MS" was already initialized
[task 2019-09-09T20:42:42.857Z] 20:42:42 INFO - must wait for load
[task 2019-09-09T20:42:42.857Z] 20:42:42 INFO - GECKO(3026) | JavaScript error: chrome://browser/content/browser-fullScreenAndPointerLock.js, line 466: Error: TelemetryStopwatch: requesting elapsed time for nonexisting stopwatch. Histogram: "FULLSCREEN_CHANGE_MS", key: ""
[task 2019-09-09T20:42:42.905Z] 20:42:42 INFO - TEST-PASS | dom/html/test/test_fullscreen-api-race.html | The window should have been closed
[task 2019-09-09T20:42:42.905Z] 20:42:42 INFO - TEST-FAIL | dom/html/test/test_fullscreen-api-race.html | The author of the test has indicated that flaky timeouts are expected. Reason: Need to wait for potential fullscreen transition
[task 2019-09-09T20:42:43.905Z] 20:42:43 INFO - Testing openNewTab, closeWindow
[task 2019-09-09T20:42:43.933Z] 20:42:43 INFO - About to enter fullscreen
[task 2019-09-09T20:42:43.956Z] 20:42:43 INFO - TEST-PASS | dom/html/test/test_fullscreen-api-race.html | Should get fullscreenchange
[task 2019-09-09T20:42:43.957Z] 20:42:43 INFO - TEST-PASS | dom/html/test/test_fullscreen-api-race.html | Should have entered fullscreen
[task 2019-09-09T20:42:43.957Z] 20:42:43 INFO - Not taking screenshot here: see the one that was previously logged
[task 2019-09-09T20:42:43.957Z] 20:42:43 INFO - TEST-UNEXPECTED-FAIL | dom/html/test/test_fullscreen-api-race.html | The window should be in fullscreen
[task 2019-09-09T20:42:43.957Z] 20:42:43 INFO - SimpleTest.ok@SimpleTest/SimpleTest.js:277:18
[task 2019-09-09T20:42:43.957Z] 20:42:43 INFO - listener@dom/html/test/test_fullscreen-api-race.html:137:11
[task 2019-09-09T20:42:43.957Z] 20:42:43 INFO - EventListener.handleEventrunTest/</<@dom/html/test/test_fullscreen-api-race.html:147:11
[task 2019-09-09T20:42:43.957Z] 20:42:43 INFO - runTest/<@dom/html/test/test_fullscreen-api-race.html:122:12
[task 2019-09-09T20:42:43.957Z] 20:42:43 INFO - promise callbackrunTest@dom/html/test/test_fullscreen-api-race.html:121:6
[task 2019-09-09T20:42:43.957Z] 20:42:43 INFO - next@dom/html/test/test_fullscreen-api-race.html:161:12
[task 2019-09-09T20:42:43.957Z] 20:42:43 INFO - focusedOrLoaded/<@SimpleTest/SimpleTest.js:805:67
[task 2019-09-09T20:42:43.957Z] 20:42:43 INFO - About to close the window
[task 2019-09-09T20:42:43.957Z] 20:42:43 INFO - TEST-PASS | dom/html/test/test_fullscreen-api-race.html | The window should have been closed
[task 2019-09-09T20:42:43.957Z] 20:42:43 INFO - TEST-FAIL | dom/html/test/test_fullscreen-api-race.html | The author of the test has indicated that flaky timeouts are expected. Reason: Need to wait for potential fullscreen transition
[task 2019-09-09T20:42:43.976Z] 20:42:43 INFO - GECKO(3026) | JavaScript error: chrome://browser/content/browser-fullScreenAndPointerLock.js, line 407: Error: TelemetryStopwatch: key "FULLSCREEN_CHANGE_MS" was already initialized
[task 2019-09-09T20:42:44.956Z] 20:42:44 INFO - Testing openNewTab, exitFullscreen
[task 2019-09-09T20:42:44.991Z] 20:42:44 INFO - About to enter fullscreen
[task 2019-09-09T20:42:45.013Z] 20:42:45 INFO - TEST-PASS | dom/html/test/test_fullscreen-api-race.html | Should get fullscreenchange
[task 2019-09-09T20:42:45.013Z] 20:42:45 INFO - TEST-PASS | dom/html/test/test_fullscreen-api-race.html | Should have entered fullscreen
[task 2019-09-09T20:42:45.013Z] 20:42:45 INFO - Not taking screenshot here: see the one that was previously logged
[task 2019-09-09T20:42:45.013Z] 20:42:45 INFO - TEST-UNEXPECTED-FAIL | dom/html/test/test_fullscreen-api-race.html | The window should be in fullscreen
[task 2019-09-09T20:42:45.013Z] 20:42:45 INFO - SimpleTest.ok@SimpleTest/SimpleTest.js:277:18
[task 2019-09-09T20:42:45.013Z] 20:42:45 INFO - listener@dom/html/test/test_fullscreen-api-race.html:137:11
[task 2019-09-09T20:42:45.013Z] 20:42:45 INFO - EventListener.handleEventrunTest/</<@dom/html/test/test_fullscreen-api-race.html:147:11
[task 2019-09-09T20:42:45.013Z] 20:42:45 INFO - runTest/<@dom/html/test/test_fullscreen-api-race.html:122:12
[task 2019-09-09T20:42:45.013Z] 20:42:45 INFO - promise callbackrunTest@dom/html/test/test_fullscreen-api-race.html:121:6
[task 2019-09-09T20:42:45.013Z] 20:42:45 INFO - next@dom/html/test/test_fullscreen-api-race.html:161:12
[task 2019-09-09T20:42:45.013Z] 20:42:45 INFO - focusedOrLoaded/<@SimpleTest/SimpleTest.js:805:67
[task 2019-09-09T20:42:45.015Z] 20:42:45 INFO - About to cancel fullscreen
[task 2019-09-09T20:42:45.033Z] 20:42:45 INFO - GECKO(3026) | JavaScript error: chrome://browser/content/browser-fullScreenAndPointerLock.js, line 407: Error: TelemetryStopwatch: key "FULLSCREEN_CHANGE_MS" was already initialized
[task 2019-09-09T20:42:45.033Z] 20:42:45 INFO - GECKO(3026) | JavaScript error: chrome://browser/content/browser-fullScreenAndPointerLock.js, line 466: Error: TelemetryStopwatch: requesting elapsed time for nonexisting stopwatch. Histogram: "FULLSCREEN_CHANGE_MS", key: ""
[task 2019-09-09T20:42:45.048Z] 20:42:45 INFO - TEST-PASS | dom/html/test/test_fullscreen-api-race.html | Should exit fullscreen
[task 2019-09-09T20:42:45.064Z] 20:42:45 INFO - GECKO(3026) | JavaScript error: chrome://browser/content/browser-fullScreenAndPointerLock.js, line 466: Error: TelemetryStopwatch: requesting elapsed time for nonexisting stopwatch. Histogram: "FULLSCREEN_CHANGE_MS", key: ""
[task 2019-09-09T20:42:45.145Z] 20:42:45 INFO - TEST-PASS | dom/html/test/test_fullscreen-api-race.html | The window should have been closed
[task 2019-09-09T20:42:45.145Z] 20:42:45 INFO - TEST-FAIL | dom/html/test/test_fullscreen-api-race.html | The author of the test has indicated that flaky timeouts are expected. Reason: Need to wait for potential fullscreen transition
[task 2019-09-09T20:42:46.149Z] 20:42:46 INFO - Testing openNewTab, exitAndClose
[task 2019-09-09T20:42:46.177Z] 20:42:46 INFO - About to enter fullscreen
[task 2019-09-09T20:42:46.199Z] 20:42:46 INFO - TEST-PASS | dom/html/test/test_fullscreen-api-race.html | Should get fullscreenchange
[task 2019-09-09T20:42:46.199Z] 20:42:46 INFO - TEST-PASS | dom/html/test/test_fullscreen-api-race.html | Should have entered fullscreen
[task 2019-09-09T20:42:46.199Z] 20:42:46 INFO - Not taking screenshot here: see the one that was previously logged
[task 2019-09-09T20:42:46.199Z] 20:42:46 INFO - TEST-UNEXPECTED-FAIL | dom/html/test/test_fullscreen-api-race.html | The window should be in fullscreen
[task 2019-09-09T20:42:46.199Z] 20:42:46 INFO - SimpleTest.ok@SimpleTest/SimpleTest.js:277:18
[task 2019-09-09T20:42:46.199Z] 20:42:46 INFO - listener@dom/html/test/test_fullscreen-api-race.html:137:11
[task 2019-09-09T20:42:46.199Z] 20:42:46 INFO - EventListener.handleEventrunTest/</<@dom/html/test/test_fullscreen-api-race.html:147:11
[task 2019-09-09T20:42:46.199Z] 20:42:46 INFO - runTest/<@dom/html/test/test_fullscreen-api-race.html:122:12
[task 2019-09-09T20:42:46.199Z] 20:42:46 INFO - promise callbackrunTest@dom/html/test/test_fullscreen-api-race.html:121:6
[task 2019-09-09T20:42:46.199Z] 20:42:46 INFO - next@dom/html/test/test_fullscreen-api-race.html:161:12
[task 2019-09-09T20:42:46.199Z] 20:42:46 INFO - focusedOrLoaded/<@SimpleTest/SimpleTest.js:805:67
[task 2019-09-09T20:42:46.199Z] 20:42:46 INFO - About to cancel fullscreen and close the window
[task 2019-09-09T20:42:46.199Z] 20:42:46 INFO - TEST-PASS | dom/html/test/test_fullscreen-api-race.html | The window should have been closed
[task 2019-09-09T20:42:46.199Z] 20:42:46 INFO - TEST-FAIL | dom/html/test/test_fullscreen-api-race.html | The author of the test has indicated that flaky timeouts are expected. Reason: Need to wait for potential fullscreen transition
[task 2019-09-09T20:42:46.214Z] 20:42:46 INFO - GECKO(3026) | JavaScript error: chrome://browser/content/browser-fullScreenAndPointerLock.js, line 407: Error: TelemetryStopwatch: key "FULLSCREEN_CHANGE_MS" was already initialized
[task 2019-09-09T20:42:47.198Z] 20:42:47 INFO - Testing openNewWindow, navigate
[task 2019-09-09T20:42:47.355Z] 20:42:47 INFO - must wait for focus
[task 2019-09-09T20:42:47.358Z] 20:42:47 INFO - About to enter fullscreen
[task 2019-09-09T20:42:47.378Z] 20:42:47 INFO - TEST-PASS | dom/html/test/test_fullscreen-api-race.html | Should get fullscreenchange
[task 2019-09-09T20:42:47.379Z] 20:42:47 INFO - TEST-PASS | dom/html/test/test_fullscreen-api-race.html | Should have entered fullscreen
[task 2019-09-09T20:42:47.380Z] 20:42:47 INFO - Not taking screenshot here: see the one that was previously logged
[task 2019-09-09T20:42:47.380Z] 20:42:47 INFO - TEST-UNEXPECTED-FAIL | dom/html/test/test_fullscreen-api-race.html | The window should be in fullscreen
[task 2019-09-09T20:42:47.380Z] 20:42:47 INFO - SimpleTest.ok@SimpleTest/SimpleTest.js:277:18
[task 2019-09-09T20:42:47.380Z] 20:42:47 INFO - listener@dom/html/test/test_fullscreen-api-race.html:137:11
[task 2019-09-09T20:42:47.380Z] 20:42:47 INFO - EventListener.handleEventrunTest/</<@dom/html/test/test_fullscreen-api-race.html:147:11
[task 2019-09-09T20:42:47.381Z] 20:42:47 INFO - runTest/<@dom/html/test/test_fullscreen-api-race.html:122:12
[task 2019-09-09T20:42:47.381Z] 20:42:47 INFO - promise callbackrunTest@dom/html/test/test_fullscreen-api-race.html:121:6
[task 2019-09-09T20:42:47.381Z] 20:42:47 INFO - next@dom/html/test/test_fullscreen-api-race.html:161:12
[task 2019-09-09T20:42:47.381Z] 20:42:47 INFO - focusedOrLoaded/<@SimpleTest/SimpleTest.js:805:67
[task 2019-09-09T20:42:47.381Z] 20:42:47 INFO - About to navigate to another page
[task 2019-09-09T20:42:47.381Z] 20:42:47 INFO - GECKO(3026) | JavaScript error: chrome://browser/content/browser-fullScreenAndPointerLock.js, line 407: Error: TelemetryStopwatch: key "FULLSCREEN_CHANGE_MS" was already initialized
[task 2019-09-09T20:42:47.381Z] 20:42:47 INFO - must wait for load
[task 2019-09-09T20:42:47.405Z] 20:42:47 INFO - GECKO(3026) | JavaScript error: chrome://browser/content/browser-fullScreenAndPointerLock.js, line 466: Error: TelemetryStopwatch: requesting elapsed time for nonexisting stopwatch. Histogram: "FULLSCREEN_CHANGE_MS", key: ""
[task 2019-09-09T20:42:47.486Z] 20:42:47 INFO - TEST-PASS | dom/html/test/test_fullscreen-api-race.html | The window should have been closed
[task 2019-09-09T20:42:47.486Z] 20:42:47 INFO - TEST-FAIL | dom/html/test/test_fullscreen-api-race.html | The author of the test has indicated that flaky timeouts are expected. Reason: Need to wait for potential fullscreen transition
[task 2019-09-09T20:42:47.493Z] 20:42:47 INFO - GECKO(3026) | JavaScript error: resource:///modules/UrlbarInput.jsm, line 231: TypeError: this._inputFieldEvents is undefined
[task 2019-09-09T20:42:48.484Z] 20:42:48 INFO - Testing openNewWindow, closeWindow
[task 2019-09-09T20:42:48.641Z] 20:42:48 INFO - must wait for focus
[task 2019-09-09T20:42:48.642Z] 20:42:48 INFO - About to enter fullscreen
[task 2019-09-09T20:42:48.656Z] 20:42:48 INFO - TEST-PASS | dom/html/test/test_fullscreen-api-race.html | Should get fullscreenchange
[task 2019-09-09T20:42:48.657Z] 20:42:48 INFO - TEST-PASS | dom/html/test/test_fullscreen-api-race.html | Should have entered fullscreen
[task 2019-09-09T20:42:48.657Z] 20:42:48 INFO - Not taking screenshot here: see the one that was previously logged
[task 2019-09-09T20:42:48.657Z] 20:42:48 INFO - TEST-UNEXPECTED-FAIL | dom/html/test/test_fullscreen-api-race.html | The window should be in fullscreen
[task 2019-09-09T20:42:48.657Z] 20:42:48 INFO - SimpleTest.ok@SimpleTest/SimpleTest.js:277:18
[task 2019-09-09T20:42:48.658Z] 20:42:48 INFO - listener@dom/html/test/test_fullscreen-api-race.html:137:11
[task 2019-09-09T20:42:48.658Z] 20:42:48 INFO - EventListener.handleEventrunTest/</<@dom/html/test/test_fullscreen-api-race.html:147:11
[task 2019-09-09T20:42:48.658Z] 20:42:48 INFO - runTest/<@dom/html/test/test_fullscreen-api-race.html:122:12
[task 2019-09-09T20:42:48.658Z] 20:42:48 INFO - promise callbackrunTest@dom/html/test/test_fullscreen-api-race.html:121:6
[task 2019-09-09T20:42:48.658Z] 20:42:48 INFO - next@dom/html/test/test_fullscreen-api-race.html:161:12
[task 2019-09-09T20:42:48.658Z] 20:42:48 INFO - focusedOrLoaded/<@SimpleTest/SimpleTest.js:805:67
[task 2019-09-09T20:42:48.658Z] 20:42:48 INFO - About to close the window
[task 2019-09-09T20:42:48.659Z] 20:42:48 INFO - TEST-PASS | dom/html/test/test_fullscreen-api-race.html | The window should have been closed
[task 2019-09-09T20:42:48.659Z] 20:42:48 INFO - TEST-FAIL | dom/html/test/test_fullscreen-api-race.html | The author of the test has indicated that flaky timeouts are expected. Reason: Need to wait for potential fullscreen transition
[task 2019-09-09T20:42:48.675Z] 20:42:48 INFO - GECKO(3026) | JavaScript error: resource:///modules/UrlbarInput.jsm, line 231: TypeError: this._inputFieldEvents is undefined
[task 2019-09-09T20:42:49.658Z] 20:42:49 INFO - Testing openNewWindow, exitFullscreen
[task 2019-09-09T20:42:49.803Z] 20:42:49 INFO - must wait for focus
[task 2019-09-09T20:42:49.810Z] 20:42:49 INFO - About to enter fullscreen
[task 2019-09-09T20:42:49.814Z] 20:42:49 INFO - GECKO(3026) | JavaScript error: chrome://browser/content/browser-fullScreenAndPointerLock.js, line 402: Error: TelemetryStopwatch: key "FULLSCREEN_CHANGE_MS" was already initialized
[task 2019-09-09T20:42:49.830Z] 20:42:49 INFO - GECKO(3026) | JavaScript error: chrome://browser/content/browser-fullScreenAndPointerLock.js, line 466: Error: TelemetryStopwatch: requesting elapsed time for nonexisting stopwatch. Histogram: "FULLSCREEN_CHANGE_MS", key: ""
[task 2019-09-09T20:42:49.830Z] 20:42:49 INFO - TEST-PASS | dom/html/test/test_fullscreen-api-race.html | Should get fullscreenchange
[task 2019-09-09T20:42:49.830Z] 20:42:49 INFO - TEST-PASS | dom/html/test/test_fullscreen-api-race.html | Should have entered fullscreen
[task 2019-09-09T20:42:49.830Z] 20:42:49 INFO - Not taking screenshot here: see the one that was previously logged
[task 2019-09-09T20:42:49.830Z] 20:42:49 INFO - TEST-UNEXPECTED-FAIL | dom/html/test/test_fullscreen-api-race.html | The window should be in fullscreen
[task 2019-09-09T20:42:49.830Z] 20:42:49 INFO - SimpleTest.ok@SimpleTest/SimpleTest.js:277:18
[task 2019-09-09T20:42:49.830Z] 20:42:49 INFO - listener@dom/html/test/test_fullscreen-api-race.html:137:11
[task 2019-09-09T20:42:49.830Z] 20:42:49 INFO - EventListener.handleEventrunTest/</<@dom/html/test/test_fullscreen-api-race.html:147:11
[task 2019-09-09T20:42:49.830Z] 20:42:49 INFO - runTest/<@dom/html/test/test_fullscreen-api-race.html:122:12
[task 2019-09-09T20:42:49.830Z] 20:42:49 INFO - promise callbackrunTest@dom/html/test/test_fullscreen-api-race.html:121:6
[task 2019-09-09T20:42:49.830Z] 20:42:49 INFO - next@dom/html/test/test_fullscreen-api-race.html:161:12
[task 2019-09-09T20:42:49.830Z] 20:42:49 INFO - focusedOrLoaded/<@SimpleTest/SimpleTest.js:805:67
[task 2019-09-09T20:42:49.830Z] 20:42:49 INFO - About to cancel fullscreen
[task 2019-09-09T20:42:49.846Z] 20:42:49 INFO - TEST-PASS | dom/html/test/test_fullscreen-api-race.html | Should exit fullscreen
[task 2019-09-09T20:42:49.942Z] 20:42:49 INFO - TEST-PASS | dom/html/test/test_fullscreen-api-race.html | The window should have been closed
[task 2019-09-09T20:42:49.942Z] 20:42:49 INFO - TEST-FAIL | dom/html/test/test_fullscreen-api-race.html | The author of the test has indicated that flaky timeouts are expected. Reason: Need to wait for potential fullscreen transition
[task 2019-09-09T20:42:49.950Z] 20:42:49 INFO - GECKO(3026) | JavaScript error: resource:///modules/UrlbarInput.jsm, line 231: TypeError: this._inputFieldEvents is undefined
[task 2019-09-09T20:42:50.949Z] 20:42:50 INFO - Testing openNewWindow, exitAndClose
[task 2019-09-09T20:42:51.091Z] 20:42:51 INFO - must wait for focus
[task 2019-09-09T20:42:51.107Z] 20:42:51 INFO - About to enter fullscreen
[task 2019-09-09T20:42:51.111Z] 20:42:51 INFO - TEST-PASS | dom/html/test/test_fullscreen-api-race.html | Should get fullscreenchange
[task 2019-09-09T20:42:51.112Z] 20:42:51 INFO - TEST-PASS | dom/html/test/test_fullscreen-api-race.html | Should have entered fullscreen
[task 2019-09-09T20:42:51.113Z] 20:42:51 INFO - Not taking screenshot here: see the one that was previously logged
[task 2019-09-09T20:42:51.113Z] 20:42:51 INFO - TEST-UNEXPECTED-FAIL | dom/html/test/test_fullscreen-api-race.html | The window should be in fullscreen
[task 2019-09-09T20:42:51.114Z] 20:42:51 INFO - SimpleTest.ok@SimpleTest/SimpleTest.js:277:18
[task 2019-09-09T20:42:51.114Z] 20:42:51 INFO - listener@dom/html/test/test_fullscreen-api-race.html:137:11
[task 2019-09-09T20:42:51.114Z] 20:42:51 INFO - EventListener.handleEventrunTest/</<@dom/html/test/test_fullscreen-api-race.html:147:11
[task 2019-09-09T20:42:51.114Z] 20:42:51 INFO - runTest/<@dom/html/test/test_fullscreen-api-race.html:122:12
[task 2019-09-09T20:42:51.114Z] 20:42:51 INFO - promise callbackrunTest@dom/html/test/test_fullscreen-api-race.html:121:6
[task 2019-09-09T20:42:51.114Z] 20:42:51 INFO - next@dom/html/test/test_fullscreen-api-race.html:161:12
[task 2019-09-09T20:42:51.114Z] 20:42:51 INFO - focusedOrLoaded/<@SimpleTest/SimpleTest.js:805:67
[task 2019-09-09T20:42:51.114Z] 20:42:51 INFO - About to cancel fullscreen and close the window
[task 2019-09-09T20:42:51.114Z] 20:42:51 INFO - TEST-PASS | dom/html/test/test_fullscreen-api-race.html | The window should have been closed
[task 2019-09-09T20:42:51.114Z] 20:42:51 INFO - TEST-FAIL | dom/html/test/test_fullscreen-api-race.html | The author of the test has indicated that flaky timeouts are expected. Reason: Need to wait for potential fullscreen transition
[task 2019-09-09T20:42:51.129Z] 20:42:51 INFO - GECKO(3026) | JavaScript error: chrome://browser/content/browser-fullScreenAndPointerLock.js, line 407: Error: TelemetryStopwatch: key "FULLSCREEN_CHANGE_MS" was already initialized
[task 2019-09-09T20:42:51.137Z] 20:42:51 INFO - GECKO(3026) | JavaScript error: resource:///modules/UrlbarInput.jsm, line 231: TypeError: this._inputFieldEvents is undefined
[task 2019-09-09T20:42:52.116Z] 20:42:52 INFO - GECKO(3026) | MEMORY STAT | vsize 2556MB | residentFast 198MB | heapAllocated 30MB
[task 2019-09-09T20:42:52.116Z] 20:42:52 INFO - TEST-OK | dom/html/test/test_fullscreen-api-race.html | took 9574ms

:hsinyi - this test began failing on linux platforms when the test image was switched from Ubuntu 16.04 to Debian 10 under the ongoing work to update our linux test environment.

Would you be able to pass on the ni for this bug and bug 1580048 (likely related) to someone that may be able to offer guidance on next steps?

To test changes against the Debian 10 image, please use ./mach try fuzzy --debian-buster flag when pushing to try.

Closing this bug as debian10 work has been halted and focus redirected to ubuntu1804, and that platform does not observe this failure.