Filed by: smolnar [at] mozilla.com
Parsed log: https://treeherder.mozilla.org/logviewer?job_id=400926980&repo=mozilla-central
Full log: https://firefox-ci-tc.services.mozilla.com/api/queue/v1/task/I5WAS7vLSHmej3S73lQJkQ/runs/0/artifacts/public/logs/live_backing.log

INFO - TEST-PASS | /webdriver/tests/new_window/new_tab.py | test_sets_no_opener 
[task 2022-12-28T23:03:22.940Z] 23:03:22     INFO - TEST-UNEXPECTED-FAIL | /webdriver/tests/new_window/new_tab.py | test_focus_content - AssertionError: assert 'false' == 'true'
[task 2022-12-28T23:03:22.940Z] 23:03:22     INFO - session = <Session edcaa7e8-4b29-4a85-95a1-6ec4c247d4eb>
[task 2022-12-28T23:03:22.940Z] 23:03:22     INFO - inline = <function inline.<locals>.inline at 0x7fdac805bae8>
[task 2022-12-28T23:03:22.940Z] 23:03:22     INFO - 
[task 2022-12-28T23:03:22.940Z] 23:03:22     INFO -     def test_focus_content(session, inline):
[task 2022-12-28T23:03:22.940Z] 23:03:22     INFO -         response = new_window(session, type_hint="tab")
[task 2022-12-28T23:03:22.941Z] 23:03:22     INFO -         value = assert_success(response)
[task 2022-12-28T23:03:22.941Z] 23:03:22     INFO -         assert value["type"] == "tab"
[task 2022-12-28T23:03:22.941Z] 23:03:22     INFO -     
[task 2022-12-28T23:03:22.941Z] 23:03:22     INFO -         session.window_handle = value["handle"]
[task 2022-12-28T23:03:22.941Z] 23:03:22     INFO -     
[task 2022-12-28T23:03:22.941Z] 23:03:22     INFO -         session.url = inline("""
[task 2022-12-28T23:03:22.942Z] 23:03:22     INFO -             <span contenteditable="true"> abc </span>
[task 2022-12-28T23:03:22.942Z] 23:03:22     INFO -             <script>
[task 2022-12-28T23:03:22.942Z] 23:03:22     INFO -                 const selection = getSelection();
[task 2022-12-28T23:03:22.942Z] 23:03:22     INFO -                 window.onload = async() => {
[task 2022-12-28T23:03:22.942Z] 23:03:22     INFO -                     const initial = document.querySelector("span");
[task 2022-12-28T23:03:22.942Z] 23:03:22     INFO -                     initial.focus();
[task 2022-12-28T23:03:22.942Z] 23:03:22     INFO -                     initial.setAttribute(
[task 2022-12-28T23:03:22.942Z] 23:03:22     INFO -                         "_focused",
[task 2022-12-28T23:03:22.942Z] 23:03:22     INFO -                         selection.anchorNode == initial.firstChild
[task 2022-12-28T23:03:22.942Z] 23:03:22     INFO -                     );
[task 2022-12-28T23:03:22.943Z] 23:03:22     INFO -                 }
[task 2022-12-28T23:03:22.943Z] 23:03:22     INFO -             </script>
[task 2022-12-28T23:03:22.943Z] 23:03:22     INFO -         """)
[task 2022-12-28T23:03:22.943Z] 23:03:22     INFO -     
[task 2022-12-28T23:03:22.943Z] 23:03:22     INFO -         elem = session.find.css("span", all=False)
[task 2022-12-28T23:03:22.943Z] 23:03:22     INFO - >       assert elem.attribute("_focused") == "true"
[task 2022-12-28T23:03:22.943Z] 23:03:22     INFO - E       AssertionError: assert 'false' == 'true'
[task 2022-12-28T23:03:22.943Z] 23:03:22     INFO - E         - true
[task 2022-12-28T23:03:22.944Z] 23:03:22     INFO - E         + false
[task 2022-12-28T23:03:22.944Z] 23:03:22     INFO - 
[task 2022-12-28T23:03:22.944Z] 23:03:22     INFO - elem       = <Element 7dc31b70-9491-4a01-bad5-d4fdf79aeab4>
[task 2022-12-28T23:03:22.944Z] 23:03:22     INFO - inline     = <function inline.<locals>.inline at 0x7fdac805bae8>
[task 2022-12-28T23:03:22.944Z] 23:03:22     INFO - response   = <[ValueError('Sign not allowed in string format specifier',) raised in repr()] Response object at 0x7fdac82c9ef0>
[task 2022-12-28T23:03:22.944Z] 23:03:22     INFO - session    = <Session edcaa7e8-4b29-4a85-95a1-6ec4c247d4eb>
INFO - value      = {'handle': '11d7b29d-6402-4e3d-9048-b2228668b040', 'type': 'tab'}
[task 2022-12-28T23:03:22.944Z] 23:03:22     INFO - 
[task 2022-12-28T23:03:22.944Z] 23:03:22     INFO - tests/web-platform/tests/webdriver/tests/new_window/new_tab.py:89: AssertionError
[task 2022-12-28T23:03:22.945Z] 23:03:22     INFO - TEST-OK | /webdriver/tests/new_window/new_tab.py | took 10430ms

This kind of failure should have basically fixed with my patch on bug 1798655. But maybe only calling this.contentBrowser?.focus(); doesn't seem to be enough and especially for slow builds it might take some time to actually set the focus to the given tab's browser.

It happened once so far for a ccov build. Lets observe for now.

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

New failure instance: https://treeherder.mozilla.org/logviewer?job_id=421310469&repo=mozilla-central