Filed by: abutkovits [at] mozilla.com
Parsed log: https://treeherder.mozilla.org/logviewer?job_id=328511114&repo=autoland
Full log: https://firefox-ci-tc.services.mozilla.com/api/queue/v1/task/TWeQLBi5Qs2yWLjSAqGjlA/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/TWeQLBi5Qs2yWLjSAqGjlA/runs/0/artifacts/public/logs/live_backing.log&only_show_unexpected=1

[task 2021-02-02T00:08:28.720Z] 00:08:28     INFO - TEST-START | /preload/link-header-preload.html
[task 2021-02-02T00:08:28.721Z] 00:08:28     INFO - Run 1/10
[task 2021-02-02T00:08:28.723Z] 00:08:28     INFO - Closing window 38
[task 2021-02-02T00:08:33.829Z] 00:08:33     INFO - PID 1222 | JavaScript error: http://web-platform.test:8000/resources/testharness.js, line 1211: uncaught exception: Error: assert_equals: resources/square.png?link-header-preload expected 1 but got 0
[task 2021-02-02T00:08:33.833Z] 00:08:33     INFO - 
[task 2021-02-02T00:08:33.834Z] 00:08:33     INFO - TEST-UNEXPECTED-FAIL | /preload/link-header-preload.html | Makes sure that Link headers preload resources - uncaught exception: Error: assert_equals: resources/square.png?link-header-preload expected 1 but got 0```

https://wiki.mozilla.org/Bug_Triage#Intermittent_Test_Failure_Cleanup
For more information, please visit auto_nag documentation.