Bug: Intermittent unknown test url | uncaught exception - TypeError: can't access property "hasLayers", initialBrowser.frameLoader.remoteTab is null at AsyncTabSwitcher@resource:///modules/AsyncTabSwitcher.jsm:170:1
Status: RESOLVED
Priority: P5
Resolution: INCOMPLETE
Created: 2022-07-25 19:23:54+00:00
Resolved: 2023-07-31 12:03:30+00:00

**Filed by:** csabou [at] mozilla.com
**Parsed log:** https://treeherder.mozilla.org/logviewer?job_id=385353190&repo=mozilla-central
**Full log:** https://firefox-ci-tc.services.mozilla.com/api/queue/v1/task/SUp_VYHkQVCxax9j--ePhQ/runs/0/artifacts/public/logs/live_backing.log

---
```
[task 2022-07-25T18:41:32.540Z] 18:41:32     INFO - GECKO(7724) | 1658774492539	Marionette	DEBUG	3 -> [0,5,"Marionette:SetContext",{"value":"chrome"}]
[task 2022-07-25T18:41:32.540Z] 18:41:32     INFO - GECKO(7724) | 1658774492539	Marionette	DEBUG	3 <- [1,5,null,{"value":null}]
[task 2022-07-25T18:41:32.552Z] 18:41:32     INFO - GECKO(7724) | 1658774492556	Marionette	DEBUG	3 -> [0,6,"WebDriver:ExecuteScript",{"script":"/* This Source Code Form is subject to the terms of the Mozilla Public\n * License, ... ewSandbox":true,"sandbox":"default","line":2015,"filename":"Z:\\task_165877222711123\\build\\tests\\mochitest\\runtests.py"}]
[task 2022-07-25T18:41:32.560Z] 18:41:32     INFO - GECKO(7724) | 1658774492560	Marionette	TRACE	[9] MarionetteCommands actor created for window id 4
[task 2022-07-25T18:41:32.574Z] 18:41:32     INFO - GECKO(7724) | 1658774492580	Marionette	TRACE	Received observer notification domwindowopened
[task 2022-07-25T18:41:32.585Z] 18:41:32     INFO - GECKO(7724) | 1658774492584	Marionette	DEBUG	3 <- [1,6,null,{"value":null}]
[task 2022-07-25T18:41:32.595Z] 18:41:32     INFO - GECKO(7724) | 1658774492595	Marionette	DEBUG	3 -> [0,7,"Marionette:SetContext",{"value":"content"}]
[task 2022-07-25T18:41:32.596Z] 18:41:32     INFO - GECKO(7724) | 1658774492595	Marionette	DEBUG	3 <- [1,7,null,{"value":null}]
[task 2022-07-25T18:41:32.597Z] 18:41:32     INFO - GECKO(7724) | 1658774492597	Marionette	DEBUG	3 -> [0,8,"WebDriver:DeleteSession",{}]
[task 2022-07-25T18:41:32.600Z] 18:41:32     INFO - GECKO(7724) | 1658774492600	Marionette	DEBUG	3 <- [1,8,null,{"value":null}]
[task 2022-07-25T18:41:32.602Z] 18:41:32     INFO - runtests.py | Waiting for browser...
[task 2022-07-25T18:41:32.603Z] 18:41:32     INFO - GECKO(7724) | 1658774492603	Marionette	DEBUG	Closed connection 3
[task 2022-07-25T18:41:32.693Z] 18:41:32     INFO - *** Start BrowserChrome Test Results ***
[task 2022-07-25T18:41:32.710Z] 18:41:32    ERROR - GECKO(7724) | TEST-UNEXPECTED-FAIL | unknown test url | uncaught exception - TypeError: can't access property "hasLayers", initialBrowser.frameLoader.remoteTab is null at AsyncTabSwitcher@resource:///modules/AsyncTabSwitcher.jsm:170:1
[task 2022-07-25T18:41:32.711Z] 18:41:32     INFO - GECKO(7724) | _getSwitcher@chrome://browser/content/tabbrowser.js:5324:26
[task 2022-07-25T18:41:32.711Z] 18:41:32     INFO - GECKO(7724) | updateCurrentBrowser@chrome://browser/content/tabbrowser.js:1076:16
[task 2022-07-25T18:41:32.712Z] 18:41:32     INFO - GECKO(7724) | _setupEventListeners/<@chrome://browser/content/tabbrowser.js:5775:16
[task 2022-07-25T18:41:32.712Z] 18:41:32     INFO - GECKO(7724) | set selectedIndex@chrome://global/content/elements/tabbox.js:204:14
[task 2022-07-25T18:41:32.713Z] 18:41:32     INFO - GECKO(7724) | set selectedPanel@chrome://global/content/elements/tabbox.js:222:7
[task 2022-07-25T18:41:32.714Z] 18:41:32     INFO - GECKO(7724) | set selectedIndex@chrome://global/content/elements/tabbox.js:546:11
[task 2022-07-25T18:41:32.715Z] 18:41:32     INFO - GECKO(7724) | set selectedItem@chrome://global/content/elements/tabbox.js:565:35
[task 2022-07-25T18:41:32.715Z] 18:41:32     INFO - GECKO(7724) | set selectedTab@chrome://global/content/elements/tabbox.js:82:11
[task 2022-07-25T18:41:32.716Z] 18:41:32     INFO - GECKO(7724) | set selectedTab@chrome://browser/content/tabbrowser.js:311:7
[task 2022-07-25T18:41:32.717Z] 18:41:32     INFO - GECKO(7724) | _blurTab@chrome://browser/content/tabbrowser.js:4265:31
[task 2022-07-25T18:41:32.717Z] 18:41:32     INFO - GECKO(7724) | _beginRemoveTab@chrome://browser/content/tabbrowser.js:3907:14
[task 2022-07-25T18:41:32.717Z] 18:41:32     INFO - GECKO(7724) | removeTab@chrome://browser/content/tabbrowser.js:3775:15
[task 2022-07-25T18:41:32.718Z] 18:41:32     INFO - GECKO(7724) | Tester_waitForWindowsState@chrome://mochikit/content/browser-test.js:421:16
[task 2022-07-25T18:41:32.719Z] 18:41:32     INFO - GECKO(7724) | nextTest@chrome://mochikit/content/browser-test.js:864:10
[task 2022-07-25T18:41:32.719Z] 18:41:32     INFO - GECKO(7724) | Tester_start/<@chrome://mochikit/content/browser-test.js:336:14
[task 2022-07-25T18:41:32.720Z] 18:41:32     INFO - GECKO(7724) | JavaScript error: resource:///modules/AsyncTabSwitcher.jsm, line 170: TypeError: can't access property "hasLayers", initialBrowser.frameLoader.remoteTab is null
[task 2022-07-25T18:41:32.721Z] 18:41:32     INFO - GECKO(7724) | Assertion failure
[task 2022-07-25T18:41:32.721Z] 18:41:32     INFO - GECKO(7724) | assert@resource:///modules/AsyncTabSwitcher.jsm:500:36
[task 2022-07-25T18:41:32.721Z] 18:41:32     INFO - GECKO(7724) | preActions@resource:///modules/AsyncTabSwitcher.jsm:567:10
[task 2022-07-25T18:41:32.722Z] 18:41:32     INFO - GECKO(7724) | handleEvent@resource:///modules/AsyncTabSwitcher.jsm:1089:12
[task 2022-07-25T18:41:32.722Z] 18:41:32     INFO - GECKO(7724) | Assertion failure
[task 2022-07-25T18:41:32.723Z] 18:41:32     INFO - GECKO(7724) | assert@resource:///modules/AsyncTabSwitcher.jsm:500:36
[task 2022-07-25T18:41:32.723Z] 18:41:32     INFO - GECKO(7724) | preActions@resource:///modules/AsyncTabSwitcher.jsm:568:10
[task 2022-07-25T18:41:32.724Z] 18:41:32     INFO - GECKO(7724) | handleEvent@resource:///modules/AsyncTabSwitcher.jsm:1089:12
[task 2022-07-25T18:41:32.724Z] 18:41:32     INFO - GECKO(7724) | JavaScript error: resource:///modules/AsyncTabSwitcher.jsm, line 625: TypeError: can't access property "isRemoteBrowser", this.requestedTab.linkedBrowser is null
[task 2022-07-25T18:41:32.725Z] 18:41:32     INFO - GECKO(7724) | Assertion failure
[task 2022-07-25T18:41:32.725Z] 18:41:32     INFO - GECKO(7724) | assert@resource:///modules/AsyncTabSwitcher.jsm:500:36
[task 2022-07-25T18:41:32.726Z] 18:41:32     INFO - GECKO(7724) | preActions@resource:///modules/AsyncTabSwitcher.jsm:567:10
[task 2022-07-25T18:41:32.726Z] 18:41:32     INFO - GECKO(7724) | handleEvent@resource:///modules/AsyncTabSwitcher.jsm:1089:12
[task 2022-07-25T18:41:32.727Z] 18:41:32     INFO - GECKO(7724) | Assertion failure
[task 2022-07-25T18:41:32.727Z] 18:41:32     INFO - GECKO(7724) | assert@resource:///modules/AsyncTabSwitcher.jsm:500:36
[task 2022-07-25T18:41:32.728Z] 18:41:32     INFO - GECKO(7724) | preActions@resource:///modules/AsyncTabSwitcher.jsm:568:10
[task 2022-07-25T18:41:32.728Z] 18:41:32     INFO - GECKO(7724) | handleEvent@resource:///modules/AsyncTabSwitcher.jsm:1089:12
[task 2022-07-25T18:41:32.729Z] 18:41:32     INFO - GECKO(7724) | JavaScript error: resource:///modules/AsyncTabSwitcher.jsm, line 625: TypeError: can't access property "isRemoteBrowser", this.requestedTab.linkedBrowser is null
[task 2022-07-25T18:41:32.732Z] 18:41:32     INFO - TEST-INFO | (browser-test.js) | Console message: [JavaScript Error: "TypeError: can't access property "hasLayers", initialBrowser.frameLoader.remoteTab is null" {file: "resource:///modules/AsyncTabSwitcher.jsm" line: 170}]
[task 2022-07-25T18:41:32.732Z] 18:41:32     INFO - AsyncTabSwitcher@resource:///modules/AsyncTabSwitcher.jsm:170:1
[task 2022-07-25T18:41:32.733Z] 18:41:32     INFO - _getSwitcher@chrome://browser/content/tabbrowser.js:5324:26
[task 2022-07-25T18:41:32.733Z] 18:41:32     INFO - updateCurrentBrowser@chrome://browser/content/tabbrowser.js:1076:16
[task 2022-07-25T18:41:32.733Z] 18:41:32     INFO - _setupEventListeners/<@chrome://browser/content/tabbrowser.js:5775:16
[task 2022-07-25T18:41:32.733Z] 18:41:32     INFO - set selectedIndex@chrome://global/content/elements/tabbox.js:204:14
[task 2022-07-25T18:41:32.733Z] 18:41:32     INFO - set selectedPanel@chrome://global/content/elements/tabbox.js:222:7
[task 2022-07-25T18:41:32.733Z] 18:41:32     INFO - set selectedIndex@chrome://global/content/elements/tabbox.js:546:11
[task 2022-07-25T18:41:32.733Z] 18:41:32     INFO - set selectedItem@chrome://global/content/elements/tabbox.js:565:35
[task 2022-07-25T18:41:32.733Z] 18:41:32     INFO - set selectedTab@chrome://global/content/elements/tabbox.js:82:11
[task 2022-07-25T18:41:32.734Z] 18:41:32     INFO - set selectedTab@chrome://browser/content/tabbrowser.js:311:7
[task 2022-07-25T18:41:32.734Z] 18:41:32     INFO - _blurTab@chrome://browser/content/tabbrowser.js:4265:31
[task 2022-07-25T18:41:32.734Z] 18:41:32     INFO - _beginRemoveTab@chrome://browser/content/tabbrowser.js:3907:14
[task 2022-07-25T18:41:32.734Z] 18:41:32     INFO - removeTab@chrome://browser/content/tabbrowser.js:3775:15
[task 2022-07-25T18:41:32.734Z] 18:41:32     INFO - Tester_waitForWindowsState@chrome://mochikit/content/browser-test.js:421:16
[task 2022-07-25T18:41:32.734Z] 18:41:32     INFO - nextTest@chrome://mochikit/content/browser-test.js:864:10
[task 2022-07-25T18:41:32.734Z] 18:41:32     INFO - Tester_start/<@chrome://mochikit/content/browser-test.js:336:14
[task 2022-07-25T18:41:32.734Z] 18:41:32     INFO - 
[task 2022-07-25T18:41:32.734Z] 18:41:32     INFO - TEST-INFO | (browser-test.js) | Console message: [JavaScript Error: "TypeError: can't access property "isRemoteBrowser", this.requestedTab.linkedBrowser is null" {file: "resource:///modules/AsyncTabSwitcher.jsm" line: 625}]
[task 2022-07-25T18:41:32.734Z] 18:41:32     INFO - postActions@resource:///modules/AsyncTabSwitcher.jsm:625:9
[task 2022-07-25T18:41:32.735Z] 18:41:32     INFO - handleEvent@resource:///modules/AsyncTabSwitcher.jsm:1127:12
```