1952238 - Intermittent Wd - webdriver.bidi.error.UnknownErrorException: unknown error (Error: Browsing context got discarded)

Status: NEW

(Remote Protocol :: WebDriver BiDi, defect, P5)

Description

[Treeherder Bug Filer]

Filed by: amarc [at] mozilla.com
Parsed log: https://treeherder.mozilla.org/logviewer?job_id=497865680&repo=mozilla-beta
Full log: https://firefox-ci-tc.services.mozilla.com/api/queue/v1/task/KpxWk7TzTLWeMzYDJusO3g/runs/0/artifacts/public/logs/live_backing.log

---

[task 2025-03-06T13:42:16.513Z] 13:42:16     INFO - STDOUT: ================================== FAILURES ===================================
[task 2025-03-06T13:42:16.514Z] 13:42:16     INFO - STDOUT: _____________________________ test_reason_phrase ______________________________
[task 2025-03-06T13:42:16.515Z] 13:42:16     INFO - STDOUT: setup_blocked_request = <function setup_blocked_request.<locals>.setup_blocked_request at 0x000001D1756B4AE0>
[task 2025-03-06T13:42:16.515Z] 13:42:16     INFO - STDOUT: subscribe_events = <function subscribe_events.<locals>.subscribe_events at 0x000001D1756B7A60>
[task 2025-03-06T13:42:16.516Z] 13:42:16     INFO - STDOUT: bidi_session = <webdriver.bidi.client.BidiSession object at 0x000001D1755BD290>
[task 2025-03-06T13:42:16.517Z] 13:42:16     INFO - STDOUT: wait_for_event = <function wait_for_event.<locals>.wait_for_event at 0x000001D174C80AE0>
[task 2025-03-06T13:42:16.519Z] 13:42:16     INFO - STDOUT: wait_for_future_safe = <function wait_for_future_safe.<locals>.wait_for_future_safe at 0x000001D175676A20>
[task 2025-03-06T13:42:16.520Z] 13:42:16     INFO - STDOUT:     async def test_reason_phrase(
[task 2025-03-06T13:42:16.521Z] 13:42:16     INFO - STDOUT:         setup_blocked_request,
[task 2025-03-06T13:42:16.521Z] 13:42:16     INFO - STDOUT:         subscribe_events,
[task 2025-03-06T13:42:16.523Z] 13:42:16     INFO - STDOUT:         bidi_session,
[task 2025-03-06T13:42:16.524Z] 13:42:16     INFO - STDOUT:         wait_for_event,
[task 2025-03-06T13:42:16.525Z] 13:42:16     INFO - STDOUT:         wait_for_future_safe,
[task 2025-03-06T13:42:16.526Z] 13:42:16     INFO - STDOUT:     ):
[task 2025-03-06T13:42:16.527Z] 13:42:16     INFO - STDOUT: >       request = await setup_blocked_request(phase="responseStarted")
[task 2025-03-06T13:42:16.527Z] 13:42:16     INFO - STDOUT: bidi_session = <webdriver.bidi.client.BidiSession object at 0x000001D1755BD290>
[task 2025-03-06T13:42:16.528Z] 13:42:16     INFO - STDOUT: setup_blocked_request = <function setup_blocked_request.<locals>.setup_blocked_request at 0x000001D1756B4AE0>
[task 2025-03-06T13:42:16.529Z] 13:42:16     INFO - STDOUT: subscribe_events = <function subscribe_events.<locals>.subscribe_events at 0x000001D1756B7A60>
[task 2025-03-06T13:42:16.530Z] 13:42:16     INFO - STDOUT: wait_for_event = <function wait_for_event.<locals>.wait_for_event at 0x000001D174C80AE0>
[task 2025-03-06T13:42:16.541Z] 13:42:16     INFO - 
[task 2025-03-06T13:42:16.541Z] 13:42:16     INFO - TEST-UNEXPECTED-FAIL | /webdriver/tests/bidi/network/continue_response/reason_phrase.py | test_reason_phrase - webdriver.bidi.error.UnknownErrorException: unknown error (Error: Browsing context got discarded)
[task 2025-03-06T13:42:16.541Z] 13:42:16     INFO - setup_blocked_request = <function setup_blocked_request.<locals>.setup_blocked_request at 0x000001D1756B4AE0>
[task 2025-03-06T13:42:16.541Z] 13:42:16     INFO - subscribe_events = <function subscribe_events.<locals>.subscribe_events at 0x000001D1756B7A60>
[task 2025-03-06T13:42:16.542Z] 13:42:16     INFO - bidi_session = <webdriver.bidi.client.BidiSession object at 0x000001D1755BD290>
[task 2025-03-06T13:42:16.542Z] 13:42:16     INFO - wait_for_event = <function wait_for_event.<locals>.wait_for_event at 0x000001D174C80AE0>
[task 2025-03-06T13:42:16.542Z] 13:42:16     INFO - wait_for_future_safe = <function wait_for_future_safe.<locals>.wait_for_future_safe at 0x000001D175676A20>
[task 2025-03-06T13:42:16.542Z] 13:42:16     INFO - 
[task 2025-03-06T13:42:16.542Z] 13:42:16     INFO -     async def test_reason_phrase(
[task 2025-03-06T13:42:16.542Z] 13:42:16     INFO -         setup_blocked_request,
[task 2025-03-06T13:42:16.542Z] 13:42:16     INFO -         subscribe_events,
[task 2025-03-06T13:42:16.542Z] 13:42:16     INFO -         bidi_session,
[task 2025-03-06T13:42:16.542Z] 13:42:16     INFO -         wait_for_event,
[task 2025-03-06T13:42:16.542Z] 13:42:16     INFO -         wait_for_future_safe,
[task 2025-03-06T13:42:16.542Z] 13:42:16     INFO -     ):
[task 2025-03-06T13:42:16.542Z] 13:42:16     INFO - >       request = await setup_blocked_request(phase="responseStarted")
[task 2025-03-06T13:42:16.542Z] 13:42:16     INFO - 
[task 2025-03-06T13:42:16.542Z] 13:42:16     INFO - bidi_session = <webdriver.bidi.client.BidiSession object at 0x000001D1755BD290>
[task 2025-03-06T13:42:16.542Z] 13:42:16     INFO - setup_blocked_request = <function setup_blocked_request.<locals>.setup_blocked_request at 0x000001D1756B4AE0>
[task 2025-03-06T13:42:16.542Z] 13:42:16     INFO - subscribe_events = <function subscribe_events.<locals>.subscribe_events at 0x000001D1756B7A60>
[task 2025-03-06T13:42:16.542Z] 13:42:16     INFO - wait_for_event = <function wait_for_event.<locals>.wait_for_event at 0x000001D174C80AE0>
[task 2025-03-06T13:42:16.542Z] 13:42:16     INFO - wait_for_future_safe = <function wait_for_future_safe.<locals>.wait_for_future_safe at 0x000001D175676A20>
[task 2025-03-06T13:42:16.543Z] 13:42:16     INFO - 
[task 2025-03-06T13:42:16.543Z] 13:42:16     INFO - tests\web-platform\tests\webdriver\tests\bidi\network\continue_response\reason_phrase.py:20: 
[task 2025-03-06T13:42:16.543Z] 13:42:16     INFO - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
[task 2025-03-06T13:42:16.543Z] 13:42:16     INFO - tests\web-platform\tests\webdriver\tests\support\fixtures_bidi.py:807: in setup_blocked_request
[task 2025-03-06T13:42:16.543Z] 13:42:16     INFO -     await setup_network_test(events=[f"network.{phase}"])
[task 2025-03-06T13:42:16.543Z] 13:42:16     INFO -         add_intercept = <function add_intercept.<locals>.add_intercept at 0x000001D1756B6AC0>
[task 2025-03-06T13:42:16.543Z] 13:42:16     INFO -         bidi_session = <webdriver.bidi.client.BidiSession object at 0x000001D1755BD290>
[task 2025-03-06T13:42:16.543Z] 13:42:16     INFO -         blocked_auth_requests = []
[task 2025-03-06T13:42:16.543Z] 13:42:16     INFO -         blocked_requests = []
[task 2025-03-06T13:42:16.543Z] 13:42:16     INFO -         blocked_url = None
[task 2025-03-06T13:42:16.543Z] 13:42:16     INFO -         context    = {'children': [],
[task 2025-03-06T13:42:16.543Z] 13:42:16     INFO -  'context': 'b725453f-193a-4733-b3d3-2949717b93f5',
[task 2025-03-06T13:42:16.543Z] 13:42:16     INFO -  'originalOpener': None,
[task 2025-03-06T13:42:16.543Z] 13:42:16     INFO -  'parent': None,
[task 2025-03-06T13:42:16.543Z] 13:42:16     INFO -  'url': 'about:blank',
[task 2025-03-06T13:42:16.543Z] 13:42:16     INFO -  'userContext': 'default'}
[task 2025-03-06T13:42:16.543Z] 13:42:16     INFO -         fetch      = <function fetch.<locals>.fetch at 0x000001D1756B6CA0>
[task 2025-03-06T13:42:16.543Z] 13:42:16     INFO -         kwargs     = {}
[task 2025-03-06T13:42:16.544Z] 13:42:16     INFO -         navigate   = False
[task 2025-03-06T13:42:16.544Z] 13:42:16     INFO -         navigate_url = None
[task 2025-03-06T13:42:16.544Z] 13:42:16     INFO -         password   = 'password'
[task 2025-03-06T13:42:16.544Z] 13:42:16     INFO -         phase      = 'responseStarted'
[task 2025-03-06T13:42:16.544Z] 13:42:16     INFO -         realm      = 'test'
[task 2025-03-06T13:42:16.544Z] 13:42:16     INFO -         setup_network_test = <function setup_network_test.<locals>._setup_network_test at 0x000001D1756B6B60>
[task 2025-03-06T13:42:16.544Z] 13:42:16     INFO -         url        = <function url.<locals>.url at 0x000001D1756B63E0>
[task 2025-03-06T13:42:16.544Z] 13:42:16     INFO -         username   = 'user'
[task 2025-03-06T13:42:16.545Z] 13:42:16     INFO -         wait_for_event = <function wait_for_event.<locals>.wait_for_event at 0x000001D174C80AE0>
[task 2025-03-06T13:42:16.545Z] 13:42:16     INFO - tests\web-platform\tests\webdriver\tests\support\fixtures_bidi.py:699: in _setup_network_test
[task 2025-03-06T13:42:16.545Z] 13:42:16     INFO -     await bidi_session.browsing_context.navigate(
[task 2025-03-06T13:42:16.545Z] 13:42:16     INFO -         bidi_session = <webdriver.bidi.client.BidiSession object at 0x000001D1755BD290>
[task 2025-03-06T13:42:16.545Z] 13:42:16     INFO -         context    = 'b725453f-193a-4733-b3d3-2949717b93f5'
[task 2025-03-06T13:42:16.545Z] 13:42:16     INFO -         contexts   = None
[task 2025-03-06T13:42:16.545Z] 13:42:16     INFO -         events     = ['network.responseStarted']
[task 2025-03-06T13:42:16.545Z] 13:42:16     INFO -         listeners  = []
[task 2025-03-06T13:42:16.545Z] 13:42:16     INFO -         on_response_completed = <Future pending>
[task 2025-03-06T13:42:16.545Z] 13:42:16     INFO -         subscribe_events = <function subscribe_events.<locals>.subscribe_events at 0x000001D1756B7A60>
[task 2025-03-06T13:42:16.545Z] 13:42:16     INFO -         test_url   = 'https://web-platform.test:8443/webdriver/tests/bidi/network/support/empty.html'
[task 2025-03-06T13:42:16.545Z] 13:42:16     INFO -         wait_for_event = <function wait_for_event.<locals>.wait_for_event at 0x000001D174C80AE0>
[task 2025-03-06T13:42:16.545Z] 13:42:16     INFO -         wait_for_future_safe = <function wait_for_future_safe.<locals>.wait_for_future_safe at 0x000001D175676A20>
[task 2025-03-06T13:42:16.545Z] 13:42:16     INFO - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
[task 2025-03-06T13:42:16.545Z] 13:42:16     INFO - 
[task 2025-03-06T13:42:16.545Z] 13:42:16     INFO - self = <webdriver.bidi.modules.browsing_context.BrowsingContext object at 0x000001D175419CD0>
[task 2025-03-06T13:42:16.545Z] 13:42:16     INFO - kwargs = {'context': 'b725453f-193a-4733-b3d3-2949717b93f5', 'url': 'https://web-platform.test:8443/webdriver/tests/bidi/network/support/empty.html', 'wait': 'complete'}
[task 2025-03-06T13:42:16.545Z] 13:42:16     INFO - raw_result = False
[task 2025-03-06T13:42:16.546Z] 13:42:16     INFO - params = {'context': 'b725453f-193a-4733-b3d3-2949717b93f5', 'url': 'https://web-platform.test:8443/webdriver/tests/bidi/network/support/empty.html', 'wait': 'complete'}
[task 2025-03-06T13:42:16.546Z] 13:42:16     INFO - mod_name = 'browsingContext', cmd_name = 'browsingContext.navigate'
[task 2025-03-06T13:42:16.546Z] 13:42:16     INFO - future = <Future finished exception=UnknownErrorException(unknown error, Error: Browsing context got discarded, #onNavigationFa...s/EventEmitter.sys.mjs:148:20
[task 2025-03-06T13:42:16.546Z] 13:42:16     INFO - observe@chrome://remote/content/shared/listeners/BrowsingContextListener.sys.mjs:84:14
[task 2025-03-06T13:42:16.546Z] 13:42:16     INFO - )>
[task 2025-03-06T13:42:16.546Z] 13:42:16     INFO - 
[task 2025-03-06T13:42:16.546Z] 13:42:16     INFO -     @functools.wraps(params_fn)
[task 2025-03-06T13:42:16.546Z] 13:42:16     INFO -     async def inner(self: Any, **kwargs: Any) -> Any:
[task 2025-03-06T13:42:16.546Z] 13:42:16     INFO -         raw_result = kwargs.pop("raw_result", False)
[task 2025-03-06T13:42:16.546Z] 13:42:16     INFO -         params = remove_undefined(params_fn(self, **kwargs))
[task 2025-03-06T13:42:16.546Z] 13:42:16     INFO -     
[task 2025-03-06T13:42:16.546Z] 13:42:16     INFO -         # Convert the classname and the method name to a bidi command name
[task 2025-03-06T13:42:16.546Z] 13:42:16     INFO -         mod_name = owner.__name__[0].lower() + owner.__name__[1:]
[task 2025-03-06T13:42:16.546Z] 13:42:16     INFO -         if hasattr(owner, "prefix"):
[task 2025-03-06T13:42:16.547Z] 13:42:16     INFO -             mod_name = f"{owner.prefix}:{mod_name}"
[task 2025-03-06T13:42:16.547Z] 13:42:16     INFO -         cmd_name = f"{mod_name}.{to_camelcase(name)}"
[task 2025-03-06T13:42:16.547Z] 13:42:16     INFO -     
[task 2025-03-06T13:42:16.547Z] 13:42:16     INFO -         future = await self.session.send_command(cmd_name, params)
[task 2025-03-06T13:42:16.547Z] 13:42:16     INFO - >       result = await future
[task 2025-03-06T13:42:16.547Z] 13:42:16     INFO - E       webdriver.bidi.error.UnknownErrorException: unknown error (Error: Browsing context got discarded)
[task 2025-03-06T13:42:16.547Z] 13:42:16     INFO - E       
[task 2025-03-06T13:42:16.547Z] 13:42:16     INFO - E       Remote-end stacktrace:
[task 2025-03-06T13:42:16.547Z] 13:42:16     INFO - E       
[task 2025-03-06T13:42:16.547Z] 13:42:16     INFO - E       #onNavigationFailed@chrome://remote/content/shared/Navigate.sys.mjs:362:26
[task 2025-03-06T13:42:16.547Z] 13:42:16     INFO - E       emit@resource://gre/modules/EventEmitter.sys.mjs:148:20
[task 2025-03-06T13:42:16.547Z] 13:42:16     INFO - E       #forwardEvent@chrome://remote/content/shared/listeners/NavigationListener.sys.mjs:93:10
[task 2025-03-06T13:42:16.547Z] 13:42:16     INFO - E       emit@resource://gre/modules/EventEmitter.sys.mjs:148:20
[task 2025-03-06T13:42:16.547Z] 13:42:16     INFO - E       #onNavigationEvent@chrome://remote/content/shared/NavigationManager.sys.mjs:726:10
[task 2025-03-06T13:42:16.547Z] 13:42:16     INFO - E       emit@resource://gre/modules/EventEmitter.sys.mjs:148:20
[task 2025-03-06T13:42:16.547Z] 13:42:16     INFO - E       notifyNavigationFailed@chrome://remote/content/shared/NavigationManager.sys.mjs:273:10
[task 2025-03-06T13:42:16.547Z] 13:42:16     INFO - E       notifyNavigationFailed@chrome://remote/content/shared/NavigationManager.sys.mjs:631:29
[task 2025-03-06T13:42:16.547Z] 13:42:16     INFO - E       #onContextDiscarded@chrome://remote/content/shared/NavigationManager.sys.mjs:550:27
[task 2025-03-06T13:42:16.547Z] 13:42:16     INFO - E       emit@resource://gre/modules/EventEmitter.sys.mjs:148:20
[task 2025-03-06T13:42:16.547Z] 13:42:16     INFO - E       observe@chrome://remote/content/shared/listeners/BrowsingContextListener.sys.mjs:84:14
[task 2025-03-06T13:42:16.547Z] 13:42:16     INFO - 
[task 2025-03-06T13:42:16.548Z] 13:42:16     INFO - cmd_name   = 'browsingContext.navigate'
[task 2025-03-06T13:42:16.548Z] 13:42:16     INFO - future     = <Future finished exception=UnknownErrorException(unknown error, Error: Browsing context got discarded, #onNavigationFailed@chrome://remote/content/shared/Navigate.sys.mjs:362:26
[task 2025-03-06T13:42:16.548Z] 13:42:16     INFO - emit@resource://gre/modules/EventEmitter.sys.mjs:148:20
[task 2025-03-06T13:42:16.548Z] 13:42:16     INFO - #forwardEvent@chrome://remote/content/shared/listeners/NavigationListener.sys.mjs:93:10
[task 2025-03-06T13:42:16.548Z] 13:42:16     INFO - emit@resource://gre/modules/EventEmitter.sys.mjs:148:20
[task 2025-03-06T13:42:16.548Z] 13:42:16     INFO - #onNavigationEvent@chrome://remote/content/shared/NavigationManager.sys.mjs:726:10
[task 2025-03-06T13:42:16.548Z] 13:42:16     INFO - emit@resource://gre/modules/EventEmitter.sys.mjs:148:20
[task 2025-03-06T13:42:16.548Z] 13:42:16     INFO - notifyNavigationFailed@chrome://remote/content/shared/NavigationManager.sys.mjs:273:10
[task 2025-03-06T13:42:16.548Z] 13:42:16     INFO - notifyNavigationFailed@chrome://remote/content/shared/NavigationManager.sys.mjs:631:29
[task 2025-03-06T13:42:16.548Z] 13:42:16     INFO - #onContextDiscarded@chrome://remote/content/shared/NavigationManager.sys.mjs:550:27
[task 2025-03-06T13:42:16.548Z] 13:42:16     INFO - emit@resource://gre/modules/EventEmitter.sys.mjs:148:20
[task 2025-03-06T13:42:16.548Z] 13:42:16     INFO - observe@chrome://remote/content/shared/listeners/BrowsingContextListener.sys.mjs:84:14
[task 2025-03-06T13:42:16.548Z] 13:42:16     INFO - )>
[task 2025-03-06T13:42:16.548Z] 13:42:16     INFO - kwargs     = {'context': 'b725453f-193a-4733-b3d3-2949717b93f5',
[task 2025-03-06T13:42:16.548Z] 13:42:16     INFO -  'url': 'https://web-platform.test:8443/webdriver/tests/bidi/network/support/empty.html',
[task 2025-03-06T13:42:16.548Z] 13:42:16     INFO -  'wait': 'complete'}
[task 2025-03-06T13:42:16.548Z] 13:42:16     INFO - mod_name   = 'browsingContext'
[task 2025-03-06T13:42:16.548Z] 13:42:16     INFO - name       = 'navigate'
[task 2025-03-06T13:42:16.548Z] 13:42:16     INFO - owner      = <class 'webdriver.bidi.modules.browsing_context.BrowsingContext'>
[task 2025-03-06T13:42:16.548Z] 13:42:16     INFO - params     = {'context': 'b725453f-193a-4733-b3d3-2949717b93f5',
[task 2025-03-06T13:42:16.549Z] 13:42:16     INFO -  'url': 'https://web-platform.test:8443/webdriver/tests/bidi/network/support/empty.html',
[task 2025-03-06T13:42:16.549Z] 13:42:16     INFO -  'wait': 'complete'}
[task 2025-03-06T13:42:16.549Z] 13:42:16     INFO - params_fn  = <function BrowsingContext.navigate at 0x000001D174E2C900>
[task 2025-03-06T13:42:16.549Z] 13:42:16     INFO - raw_result = False
[task 2025-03-06T13:42:16.549Z] 13:42:16     INFO - result_fn  = <function BrowsingContext._navigate at 0x000001D174E2C9A0>
[task 2025-03-06T13:42:16.549Z] 13:42:16     INFO - self       = <webdriver.bidi.modules.browsing_context.BrowsingContext object at 0x000001D175419CD0>
[task 2025-03-06T13:42:16.549Z] 13:42:16     INFO - 
[task 2025-03-06T13:42:16.549Z] 13:42:16     INFO - tests\web-platform\tests\tools\webdriver\webdriver\bidi\modules\_module.py:76: UnknownErrorException
[task 2025-03-06T13:42:16.550Z] 13:42:16     INFO - .
[task 2025-03-06T13:42:16.550Z] 13:42:16     INFO - TEST-OK | /webdriver/tests/bidi/network/continue_response/reason_phrase.py | took 6067ms

Comment 1

[Intermittent Failures Robot]

Summary

7 failures in 4009 pushes (0.002 failures/push) were associated with this bug in the last 7 days.

Repository breakdown:

• mozilla-central: 2
• mozilla-beta: 5

Platform and build breakdown:

• linux1804-64-ccov-qr: 2
  • opt: 2
• macosx1470-64-devedition: 1
  • opt: 1
• macosx1470-64: 3
  • opt: 3
• windows11-64-24h2: 1
  • opt: 1

Table

	headless	no_variant
linux1804-64-ccov-qr--/opt	2
macosx1470-64-devedition--/opt		1
macosx1470-64--/opt	2	1
windows11-64-24h2--/opt		1

For more details, see:

https://treeherder.mozilla.org/intermittent-failures/bugdetails?bug=1952238&startday=2025-03-03&endday=2025-03-09&tree=all

Comment 2

[Intermittent Failures Robot]

Summary

8 failures in 4826 pushes (0.002 failures/push) were associated with this bug in the last 7 days.

Repository breakdown:

• mozilla-central: 3
• try: 1
• autoland: 2
• mozilla-beta: 2

Platform and build breakdown:

• linux1804-64-ccov-qr: 3
  • opt: 3
• linux1804-64-qr: 1
  • debug: 1
• macosx1470-64: 3
  • opt: 3
• windows11-64-24h2-devedition: 1
  • opt: 1

Table

	headless	no_variant
linux1804-64-ccov-qr--/opt	2	1
linux1804-64-qr--/debug		1
macosx1470-64--/opt		3
windows11-64-24h2-devedition--/opt		1

For more details, see:

https://treeherder.mozilla.org/intermittent-failures/bugdetails?bug=1952238&startday=2025-03-10&endday=2025-03-16&tree=all

Comment 3

[Henrik Skupin [:whimboo][⌚️UTC+2]]

This is happening quite a lot these days for nearly each and every test job, but not necessarily causing a failure in the test given that it is an INFO line only:

https://treeherder.mozilla.org/logviewer?job_id=499337244&repo=mozilla-central&lineNumber=16667

[task 2025-03-15T23:09:39.618Z] 23:09:39     INFO - webdriver.bidi.error.UnknownErrorException: unknown error (Error: Browsing context got discarded)
[task 2025-03-15T23:09:39.618Z] 23:09:39     INFO - Remote-end stacktrace:
[task 2025-03-15T23:09:39.618Z] 23:09:39     INFO - #onNavigationFailed@chrome://remote/content/shared/Navigate.sys.mjs:362:26
[task 2025-03-15T23:09:39.618Z] 23:09:39     INFO - emit@resource://gre/modules/EventEmitter.sys.mjs:148:20
[task 2025-03-15T23:09:39.619Z] 23:09:39     INFO - #forwardEvent@chrome://remote/content/shared/listeners/NavigationListener.sys.mjs:93:10
[task 2025-03-15T23:09:39.619Z] 23:09:39     INFO - emit@resource://gre/modules/EventEmitter.sys.mjs:148:20
[task 2025-03-15T23:09:39.619Z] 23:09:39     INFO - #onNavigationEvent@chrome://remote/content/shared/NavigationManager.sys.mjs:726:10
[task 2025-03-15T23:09:39.619Z] 23:09:39     INFO - emit@resource://gre/modules/EventEmitter.sys.mjs:148:20
[task 2025-03-15T23:09:39.620Z] 23:09:39     INFO - notifyNavigationFailed@chrome://remote/content/shared/NavigationManager.sys.mjs:273:10
[task 2025-03-15T23:09:39.620Z] 23:09:39     INFO - notifyNavigationFailed@chrome://remote/content/shared/NavigationManager.sys.mjs:631:29
[task 2025-03-15T23:09:39.620Z] 23:09:39     INFO - #onContextDiscarded@chrome://remote/content/shared/NavigationManager.sys.mjs:550:27
[task 2025-03-15T23:09:39.621Z] 23:09:39     INFO - emit@resource://gre/modules/EventEmitter.sys.mjs:148:20
[task 2025-03-15T23:09:39.621Z] 23:09:39     INFO - observe@chrome://remote/content/shared/listeners/BrowsingContextListener.sys.mjs:84:14
[task 2025-03-15T23:09:39.621Z] 23:09:39     INFO - _endRemoveTab@chrome://browser/content/tabbrowser/tabbrowser.js:4964:15
[task 2025-03-15T23:09:39.622Z] 23:09:39     INFO - removeTab@chrome://browser/content/tabbrowser/tabbrowser.js:4613:14
[task 2025-03-15T23:09:39.622Z] 23:09:39     INFO - removeTab@chrome://remote/content/shared/TabManager.sys.mjs:420:22
[task 2025-03-15T23:09:39.622Z] 23:09:39     INFO - close@chrome://remote/content/webdriver-bidi/modules/root/browsingContext.sys.mjs:529:27
[task 2025-03-15T23:09:39.622Z] 23:09:39     INFO - handleCommand@chrome://remote/content/shared/messagehandler/MessageHandler.sys.mjs:260:33
[task 2025-03-15T23:09:39.623Z] 23:09:39     INFO - execute@chrome://remote/content/shared/webdriver/Session.sys.mjs:390:32
[task 2025-03-15T23:09:39.623Z] 23:09:39     INFO - onPacket@chrome://remote/content/webdriver-bidi/WebDriverBiDiConnection.sys.mjs:236:37
[task 2025-03-15T23:09:39.623Z] 23:09:39     INFO - onMessage@chrome://remote/content/server/WebSocketTransport.sys.mjs:127:18
[task 2025-03-15T23:09:39.624Z] 23:09:39     INFO - handleEvent@chrome://remote/content/server/WebSocketTransport.sys.mjs:109:14
[task 2025-03-15T23:09:39.668Z] 23:09:39     INFO - Closing logging queue

From the stack I can see that we are actually closing the current tab, so maybe this is a race condition somewhere that we are not waiting for a navigation to finish before closing the tab? The test bidi/browsing_context/user_prompt_opened/user_prompt_opened.py seems to come up a lot.