Filed by: dluca [at] mozilla.com
Parsed log: https://treeherder.mozilla.org/logviewer?job_id=327174019&repo=autoland
Full log: https://firefox-ci-tc.services.mozilla.com/api/queue/v1/task/dGfoUYaZS3SmfJTGg3nsAw/runs/0/artifacts/public/logs/live_backing.log
Reftest URL: https://hg.mozilla.org/mozilla-central/raw-file/tip/layout/tools/reftest/reftest-analyzer.xhtml#logurl=https://firefox-ci-tc.services.mozilla.com/api/queue/v1/task/dGfoUYaZS3SmfJTGg3nsAw/runs/0/artifacts/public/logs/live_backing.log&only_show_unexpected=1

INFO - TEST-START | /feature-policy/experimental-features/vertical-scroll-disabled-scrollbar-tentative.html
[task 2021-01-19T18:14:24.162Z] 18:14:24     INFO - Setting pref dom.security.featurePolicy.experimental.enabled (true)
[task 2021-01-19T18:14:24.174Z] 18:14:24     INFO - Setting pref dom.payments.request.enabled (true)
[task 2021-01-19T18:14:24.182Z] 18:14:24     INFO - Setting pref dom.reporting.enabled (true)
[task 2021-01-19T18:14:24.195Z] 18:14:24     INFO - Setting pref dom.reporting.featurePolicy.enabled (true)
[task 2021-01-19T18:14:24.198Z] 18:14:24     INFO - Setting pref dom.security.featurePolicy.header.enabled (true)
[task 2021-01-19T18:14:24.211Z] 18:14:24     INFO - Setting pref dom.security.featurePolicy.webidl.enabled (true)
[task 2021-01-19T18:14:24.226Z] 18:14:24     INFO - Setting pref dom.webmidi.enabled (true)
[task 2021-01-19T18:14:24.234Z] 18:14:24     INFO - Setting pref dom.vr.enabled (true)
[task 2021-01-19T18:14:24.269Z] 18:14:24     INFO - PID 25718 | 1611080064268	Marionette	INFO	Testing http://web-platform.test:8000/feature-policy/experimental-features/vertical-scroll-disabled-scrollbar-tentative.html == http://web-platform.test:8000/feature-policy/experimental-features/resources/vertical-scroll-scrollbar-ref.html?no-vertical-scrollbar
[task 2021-01-19T18:14:25.757Z] 18:14:25     INFO - PID 25718 | 1611080065756	Marionette	INFO	No differences allowed
[task 2021-01-19T18:14:25.764Z] 18:14:25     INFO - TEST-FAIL | /feature-policy/experimental-features/vertical-scroll-disabled-scrollbar-tentative.html | took 1608ms
[task 2021-01-19T18:14:25.766Z] 18:14:25     INFO - Restarting browser for new test group
[task 2021-01-19T18:14:25.806Z] 18:14:25     INFO - PID 25718 | 1611080065804	Marionette	INFO	Stopped listening on port 37324
[task 2021-01-19T18:14:26.252Z] 18:14:26     INFO - Browser exited with return code 0
[task 2021-01-19T18:14:26.252Z] 18:14:26     INFO - PROCESS LEAKS None
[task 2021-01-19T18:14:26.254Z] 18:14:26     INFO - Closing logging queue
[task 2021-01-19T18:14:26.255Z] 18:14:26     INFO - queue closed
[task 2021-01-19T18:14:26.273Z] 18:14:26     INFO - Application command: /builds/worker/workspace/build/application/firefox/firefox --marionette about:blank -profile /tmp/tmpl65rq6gq
[task 2021-01-19T18:14:26.281Z] 18:14:26     INFO - Starting runner
[task 2021-01-19T18:14:27.187Z] 18:14:27     INFO - PID 26071 | console.warn: SearchSettings: "get: No settings file exists, new profile?" (new Error("", "(unknown module)"))
[task 2021-01-19T18:14:27.954Z] 18:14:27     INFO - PID 26071 | 1611080067953	Marionette	INFO	Listening on port 38811
[task 2021-01-19T18:14:28.052Z] 18:14:28     INFO - TEST-START | /forced-colors-mode/backplate/forced-colors-mode-backplate-01.html
[task 2021-01-19T18:14:28.127Z] 18:14:28     INFO - PID 26071 | 1611080068125	Marionette	INFO	Testing http://web-platform.test:8000/forced-colors-mode/backplate/forced-colors-mode-backplate-01.html == http://web-platform.test:8000/forced-colors-mode/backplate/forced-colors-mode-backplate-01-ref.html
[task 2021-01-19T18:14:29.128Z] 18:14:29     INFO - TEST-UNEXPECTED-ERROR | /forced-colors-mode/backplate/forced-colors-mode-backplate-01.html | Testing http://web-platform.test:8000/forced-colors-mode/backplate/forced-colors-mode-backplate-01.html == http://web-platform.test:8000/forced-colors-mode/backplate/forced-colors-mode-backplate-01-ref.html
[task 2021-01-19T18:14:29.129Z] 18:14:29     INFO - TypeError: can't access property "getActor", browsingContext.currentWindowGlobal is null
[task 2021-01-19T18:14:29.129Z] 18:14:29     INFO - loadTestUrl@chrome://marionette/content/reftest.js:672:21
[task 2021-01-19T18:14:29.129Z] 18:14:29     INFO - screenshot@chrome://marionette/content/reftest.js:737:18
[task 2021-01-19T18:14:29.129Z] 18:14:29     INFO - compareUrls@chrome://marionette/content/reftest.js:489:29
[task 2021-01-19T18:14:29.129Z] 18:14:29     INFO - REFTEST   IMAGE 1 (TEST): data:image/png;base64,
[task 2021-01-19T18:14:29.130Z] 18:14:29     INFO - REFTEST   IMAGE 2 (REFERENCE): data:image/png;base64,
[task 2021-01-19T18:14:29.130Z] 18:14:29     INFO - TEST-INFO expected FAIL | took 1072ms
[task 2021-01-19T18:14:29.197Z] 18:14:29     INFO - PID 26071 | 1611080069196	Marionette	INFO	Stopped listening on port 38811
[task 2021-01-19T18:14:29.643Z] 18:14:29     INFO - Browser exited with return code 0
[task 2021-01-19T18:14:29.643Z] 18:14:29     INFO - PROCESS LEAKS None
[task 2021-01-19T18:14:29.644Z] 18:14:29     INFO - Closing logging queue
[task 2021-01-19T18:14:29.644Z] 18:14:29     INFO - queue closed
[task 2021-01-19T18:14:29.657Z] 18:14:29     INFO - Application command: /builds/worker/workspace/build/application/firefox/firefox --marionette about:blank -profile /tmp/tmpuptsc989
[task 2021-01-19T18:14:29.665Z] 18:14:29     INFO - Starting runner
[task 2021-01-19T18:14:31.096Z] 18:14:31     INFO - PID 26419 | console.warn: SearchSettings: "get: No settings file exists, new profile?" (new Error("", "(unknown module)"))
[task 2021-01-19T18:14:31.701Z] 18:14:31     INFO - PID 26419 | 1611080071700	Marionette	INFO	Listening on port 58603
[task 2021-01-19T18:14:31.814Z] 18:14:31     INFO - TEST-START | /forced-colors-mode/backplate/forced-colors-mode-backplate-02.html```