Filed by: apavel [at] mozilla.com
Parsed log: https://treeherder.mozilla.org/logviewer.html#?job_id=275512664&repo=mozilla-central
Full log: https://firefox-ci-tc.services.mozilla.com/api/queue/v1/task/Gl-Prm9yTdGedqXv4jpDHw/runs/0/artifacts/public/logs/live_backing.log

[task 2019-11-10T00:55:17.777Z] 00:55:17 INFO - TEST-START | dom/media/test/marionette/test_youtube.py YoutubeTest.test_stream_480p
[task 2019-11-10T00:55:17.779Z] 00:55:17 INFO - 1573347317773 Marionette DEBUG Accepted connection 3 from 127.0.0.1:50218
[task 2019-11-10T00:55:17.779Z] 00:55:17 INFO - 1573347317774 Marionette DEBUG 3 -> [0,1,"WebDriver:NewSession",{"strictFileInteractability":true}]
[task 2019-11-10T00:55:17.779Z] 00:55:17 INFO - 1573347317776 Marionette TRACE [17] Frame script loaded
[task 2019-11-10T00:55:17.779Z] 00:55:17 INFO - 1573347317777 Marionette TRACE [17] Frame script registered
[task 2019-11-10T00:55:17.781Z] 00:55:17 INFO - 1573347317779 Marionette DEBUG 3 <- [1,1,null,{"sessionId":"eea4dd78-f51e-3c4b-821c-f9ad4a1e2642","capabilities":{"browserName":"firefox","browserVersion":"72.0a ... /T/tmpvIq70R.mozrunner","moz:shutdownTimeout":60000,"moz:useNonSpecCompliantPointerOrigin":false,"moz:webdriverClick":true}}]
[task 2019-11-10T00:55:17.837Z] 00:55:17 INFO - 1573347317812 Marionette DEBUG 3 -> [0,2,"WebDriver:SetTimeouts",{"script":30000}]
[task 2019-11-10T00:55:17.837Z] 00:55:17 INFO - 1573347317813 Marionette DEBUG 3 <- [1,2,null,{"value":null}]
[task 2019-11-10T00:55:17.838Z] 00:55:17 INFO - 1573347317816 Marionette DEBUG 3 -> [0,3,"WebDriver:SetTimeouts",{"pageLoad":300000}]
[task 2019-11-10T00:55:17.839Z] 00:55:17 INFO - 1573347317816 Marionette DEBUG 3 <- [1,3,null,{"value":null}]
[task 2019-11-10T00:55:17.839Z] 00:55:17 INFO - 1573347317817 Marionette DEBUG 3 -> [0,4,"WebDriver:SetTimeouts",{"implicit":0}]
[task 2019-11-10T00:55:17.839Z] 00:55:17 INFO - 1573347317818 Marionette DEBUG 3 <- [1,4,null,{"value":null}]
[task 2019-11-10T00:55:17.839Z] 00:55:17 INFO - 1573347317819 Marionette DEBUG 3 -> [0,5,"Marionette:GetContext",{}]
[task 2019-11-10T00:55:17.839Z] 00:55:17 INFO - 1573347317819 Marionette DEBUG 3 <- [1,5,null,{"value":"content"}]
[task 2019-11-10T00:55:17.839Z] 00:55:17 INFO - 1573347317822 Marionette DEBUG 3 -> [0,6,"Marionette:SetContext",{"value":"chrome"}]
[task 2019-11-10T00:55:17.839Z] 00:55:17 INFO - 1573347317823 Marionette DEBUG 3 <- [1,6,null,{"value":null}]
[task 2019-11-10T00:55:17.840Z] 00:55:17 INFO - 1573347317828 Marionette DEBUG 3 -> [0,7,"WebDriver:ExecuteScript",{"script":"Components.utils.import("resource://gre/modules/Preferences.jsm");\n\n ... 1,false],"filename":"../../venv/lib/python2.7/site-packages/marionette_driver/marionette.py","sandbox":"default","line":766}]
[task 2019-11-10T00:55:17.840Z] 00:55:17 INFO - 1573347317831 Marionette DEBUG 3 <- [1,7,null,{"value":null}]
[task 2019-11-10T00:55:17.851Z] 00:55:17 INFO - 1573347317839 Marionette DEBUG 3 -> [0,8,"Marionette:SetContext",{"value":"content"}]
[task 2019-11-10T00:55:17.851Z] 00:55:17 INFO - 1573347317839 Marionette DEBUG 3 <- [1,8,null,{"value":null}]
[task 2019-11-10T00:55:17.851Z] 00:55:17 INFO - 1573347317841 Marionette DEBUG 3 -> [0,9,"Marionette:GetContext",{}]
[task 2019-11-10T00:55:17.851Z] 00:55:17 INFO - 1573347317841 Marionette DEBUG 3 <- [1,9,null,{"value":"content"}]
[task 2019-11-10T00:55:17.852Z] 00:55:17 INFO - 1573347317842 Marionette DEBUG 3 -> [0,10,"Marionette:SetContext",{"value":"chrome"}]
[task 2019-11-10T00:55:17.852Z] 00:55:17 INFO - 1573347317843 Marionette DEBUG 3 <- [1,10,null,{"value":null}]
[task 2019-11-10T00:55:17.852Z] 00:55:17 INFO - 1573347317845 Marionette DEBUG 3 -> [0,11,"WebDriver:ExecuteScript",{"script":"Components.utils.import("resource://gre/modules/Preferences.jsm");\n\n ... e,false],"filename":"../../venv/lib/python2.7/site-packages/marionette_driver/marionette.py","sandbox":"default","line":766}]
[task 2019-11-10T00:55:17.852Z] 00:55:17 INFO - 1573347317847 Marionette DEBUG 3 <- [1,11,null,{"value":null}]
[task 2019-11-10T00:55:17.855Z] 00:55:17 INFO - 1573347317849 Marionette DEBUG 3 -> [0,12,"Marionette:SetContext",{"value":"content"}]
[task 2019-11-10T00:55:17.855Z] 00:55:17 INFO - 1573347317850 Marionette DEBUG 3 <- [1,12,null,{"value":null}]
[task 2019-11-10T00:55:17.859Z] 00:55:17 INFO - mozproxy mitmproxy was not provided with a 'playback_version' Using default playback version: 4.0.4
[task 2019-11-10T00:55:17.859Z] 00:55:17 INFO - mozproxy mozproxy_dir used for mitmproxy downloads and exe files: /Users/cltbld/tasks/task_1573347212/testing/mozproxy
[task 2019-11-10T00:55:17.860Z] 00:55:17 INFO - mozproxy create mitmproxy 4.0.4 dir
[task 2019-11-10T00:55:17.860Z] 00:55:17 INFO - mozproxy downloading mitmproxy binary
[task 2019-11-10T00:55:18.105Z] 00:55:18 INFO - mozproxy INFO - File mitmproxy-4.0.4-osx.tar.gz retrieved from local cache /builds/tooltool_cache

[task 2019-11-10T00:55:19.075Z] 00:55:19 INFO - mozproxy Stopping mitmproxy playback, killing process 1503
[task 2019-11-10T00:55:19.090Z] 00:55:19 INFO - 1573347319066 Marionette DEBUG 4 <- [1,3,{"error":"unknown error","message":"Reached error page: about:neterror?e=dnsNotFound&u=https%3A//www.youtube.com/watch%3 ... 589:21\nregisterSelf@chrome://marionette/content/listener.js:501:5\n@chrome://marionette/content/listener.js:1807:1\n"},null]
[task 2019-11-10T00:55:19.160Z] 00:55:19 INFO - mozproxy Mitmproxy exited with error code -15
[task 2019-11-10T00:55:19.161Z] 00:55:19 INFO - mozproxy Turning off the browser proxy
[task 2019-11-10T00:55:19.161Z] 00:55:19 INFO - mozproxy writing: /Users/cltbld/tasks/task_1573347212/build/application/Firefox Nightly.app/Contents/Resources/distribution/policies.json
[task 2019-11-10T00:55:19.161Z] 00:55:19 INFO - 1573347319131 Marionette DEBUG 4 -> [0,4,"Marionette:GetContext",{}]
[task 2019-11-10T00:55:19.162Z] 00:55:19 INFO - 1573347319131 Marionette DEBUG 4 <- [1,4,null,{"value":"content"}]
[task 2019-11-10T00:55:19.162Z] 00:55:19 INFO - 1573347319132 Marionette DEBUG 4 -> [0,5,"Marionette:SetContext",{"value":"chrome"}]
[task 2019-11-10T00:55:19.163Z] 00:55:19 INFO - 1573347319132 Marionette DEBUG 4 <- [1,5,null,{"value":null}]
[task 2019-11-10T00:55:19.163Z] 00:55:19 INFO - 1573347319133 Marionette DEBUG 4 -> [0,6,"WebDriver:TakeScreenshot",{"full":true,"hash":false,"id":null,"scroll":true}]
[task 2019-11-10T00:55:19.194Z] 00:55:19 INFO - 1573347319189 Marionette DEBUG 4 <- [1,6,null,{"value":"iVBORw0KGgoAAAANSUhEUgAABQAAAAPxCAYAAACl+gBxAAAgAElEQVR4nOzdeXhV9Z0/8PvPPM/8ptp2WtuObWemta2tzmhrJyjuYt13c ... AAAIAxAQgAAAAAYwIQAAAAAMYEIAAAAACMCUAAAAAAGBOAAAAAADAmAAEAAABgTAACAAAAwJgABAAAAIAxAQgAAAAAYwFphn4t9+KODwAAAABJRU5ErkJggg=="}]
[task 2019-11-10T00:55:19.195Z] 00:55:19 INFO - 1573347319192 Marionette DEBUG 4 -> [0,7,"Marionette:SetContext",{"value":"content"}]
[task 2019-11-10T00:55:19.195Z] 00:55:19 INFO - 1573347319193 Marionette DEBUG 4 <- [1,7,null,{"value":null}]
[task 2019-11-10T00:55:19.195Z] 00:55:19 INFO - 1573347319194 Marionette DEBUG 4 -> [0,8,"Marionette:GetContext",{}]
[task 2019-11-10T00:55:19.195Z] 00:55:19 INFO - 1573347319194 Marionette DEBUG 4 <- [1,8,null,{"value":"content"}]
[task 2019-11-10T00:55:19.197Z] 00:55:19 INFO - 1573347319196 Marionette DEBUG 4 -> [0,9,"Marionette:SetContext",{"value":"content"}]
[task 2019-11-10T00:55:19.197Z] 00:55:19 INFO - 1573347319196 Marionette DEBUG 4 <- [1,9,null,{"value":null}]
[task 2019-11-10T00:55:19.199Z] 00:55:19 INFO - 1573347319197 Marionette DEBUG 4 -> [0,10,"WebDriver:GetPageSource",{}]
[task 2019-11-10T00:55:19.239Z] 00:55:19 INFO - TEST-UNEXPECTED-ERROR | dom/media/test/marionette/test_youtube.py YoutubeTest.test_stream_480p | UnknownException: Reached error page: about:neterror?e=dnsNotFound&u=https%3A//www.youtube.com/watch%3Fv%3DBZP1rYjoBgI&c=UTF-8&f=regular&d=We%20can%E2%80%99t%20connect%20to%20the%20server%20at%20www.youtube.com.
[task 2019-11-10T00:55:19.240Z] 00:55:19 INFO - stacktrace:
[task 2019-11-10T00:55:19.240Z] 00:55:19 INFO - WebDriverError@chrome://marionette/content/error.js:175:5
[task 2019-11-10T00:55:19.240Z] 00:55:19 INFO - UnknownError@chrome://marionette/content/error.js:482:5
[task 2019-11-10T00:55:19.240Z] 00:55:19 INFO - handleReadyState@chrome://marionette/content/listener.js:297:13
[task 2019-11-10T00:55:19.240Z] 00:55:19 INFO - handleEvent@chrome://marionette/content/listener.js:263:14
[task 2019-11-10T00:55:19.240Z] 00:55:19 INFO - EventListener.handleEventhandleEvent@chrome://marionette/content/listener.js:251:25
[task 2019-11-10T00:55:19.240Z] 00:55:19 INFO - EventListener.handleEventstart@chrome://marionette/content/listener.js:159:23
[task 2019-11-10T00:55:19.240Z] 00:55:19 INFO - navigate@chrome://marionette/content/listener.js:442:12
[task 2019-11-10T00:55:19.240Z] 00:55:19 INFO - get@chrome://marionette/content/listener.js:1136:18
[task 2019-11-10T00:55:19.240Z] 00:55:19 INFO - MessageListener.receiveMessage*startListeners@chrome://marionette/content/listener.js:589:21
[task 2019-11-10T00:55:19.241Z] 00:55:19 INFO - registerSelf@chrome://marionette/content/listener.js:501:5
[task 2019-11-10T00:55:19.241Z] 00:55:19 INFO - @chrome://marionette/content/listener.js:1807:1
[task 2019-11-10T00:55:19.241Z] 00:55:19 INFO - Traceback (most recent call last):
[task 2019-11-10T00:55:19.241Z] 00:55:19 INFO - File "/Users/cltbld/tasks/task_1573347212/build/venv/lib/python2.7/site-packages/marionette_harness/marionette_test/testcases.py", line 159, in run
[task 2019-11-10T00:55:19.242Z] 00:55:19 INFO - testMethod()
[task 2019-11-10T00:55:19.242Z] 00:55:19 INFO - File "/Users/cltbld/tasks/task_1573347212/build/tests/marionette/tests/dom/media/test/marionette/test_youtube.py", line 21, in test_stream_480p
[task 2019-11-10T00:55:19.242Z] 00:55:19 INFO - res = page.run_test()
[task 2019-11-10T00:55:19.242Z] 00:55:19 INFO - File "/Users/cltbld/tasks/task_1573347212/build/tests/marionette/tests/dom/media/test/marionette/yttest/ytpage.py", line 73, in run_test
[task 2019-11-10T00:55:19.242Z] 00:55:19 INFO - self.start_video()
[task 2019-11-10T00:55:19.242Z] 00:55:19 INFO - File "/Users/cltbld/tasks/task_1573347212/build/tests/marionette/tests/dom/media/test/marionette/yttest/ytpage.py", line 69, in start_video
[task 2019-11-10T00:55:19.242Z] 00:55:19 INFO - self.marionette.navigate(self.url)
[task 2019-11-10T00:55:19.242Z] 00:55:19 INFO - File "/Users/cltbld/tasks/task_1573347212/build/venv/lib/python2.7/site-packages/marionette_driver/marionette.py", line 1467, in navigate
[task 2019-11-10T00:55:19.242Z] 00:55:19 INFO - {"url": url})
[task 2019-11-10T00:55:19.242Z] 00:55:19 INFO - File "/Users/cltbld/tasks/task_1573347212/build/venv/lib/python2.7/site-packages/marionette_driver/decorators.py", line 26, in _
[task 2019-11-10T00:55:19.242Z] 00:55:19 INFO - return func(*args, **kwargs)
[task 2019-11-10T00:55:19.242Z] 00:55:19 INFO - File "/Users/cltbld/tasks/task_1573347212/build/venv/lib/python2.7/site-packages/marionette_driver/marionette.py", line 598, in _send_message
[task 2019-11-10T00:55:19.242Z] 00:55:19 INFO - self._handle_error(err)
[task 2019-11-10T00:55:19.242Z] 00:55:19 INFO - File "/Users/cltbld/tasks/task_1573347212/build/venv/lib/python2.7/site-packages/marionette_driver/marionette.py", line 618, in _handle_error
[task 2019-11-10T00:55:19.242Z] 00:55:19 INFO - raise errors.lookup(error)(message, stacktrace=stacktrace)
[task 2019-11-10T00:55:19.242Z] 00:55:19 INFO - TEST-INFO took 1441ms
[task 2019-11-10T00:55:19.242Z] 00:55:19 INFO - 1573347319208 Marionette DEBUG 4 <- [1,10,null,{"value":"<html xmlns="http://www.w3.org/1999/xhtml" dir="ltr" lang="en-US">\n <head>\n <meta http-equiv ... /div>\n </div>\n </div>\n </body>\n <script src="chrome://browser/content/aboutNetError.js"></script>\n</html>"}]
[task 2019-11-10T00:55:19.242Z] 00:55:19 INFO - 1573347319209 Marionette DEBUG 4 -> [0,11,"Marionette:SetContext",{"value":"content"}]
[task 2019-11-10T00:55:19.242Z] 00:55:19 INFO - 1573347319210 Marionette DEBUG 4 <- [1,11,null,{"value":null}]
[task 2019-11-10T00:55:19.242Z] 00:55:19 INFO - 1573347319214 Marionette DEBUG 4 -> [0,12,"WebDriver:DeleteSession",{}]

Seems to be fixed by commit https://hg.mozilla.org/mozilla-central/rev/7a75cab3dd550b77ba4f748b31c1b45ce2784c84

https://treeherder.mozilla.org/#/jobs?repo=mozilla-central&group_state=expanded&selectedJob=275507283&resultStatus=success%2Ctestfailed%2Cbusted%2Cexception&searchStr=os%2Cx%2C10.14%2Cshippable%2Copt%2Ctest-macosx1014-64-shippable%2Fopt-marionette-media-e10s%2C%28mnm%29