Filed by: mlaza [at] mozilla.com
Parsed log: https://treeherder.mozilla.org/logviewer?job_id=382038676&repo=autoland
Full log: https://firefox-ci-tc.services.mozilla.com/api/queue/v1/task/VdDdf4c_SXeh67wlge4jUw/runs/0/artifacts/public/logs/live_backing.log

[task 2022-06-21T14:30:31.076Z] 14:30:31     INFO - TEST-PASS | devtools/client/framework/browser-toolbox/test/browser_browser_toolbox_netmonitor.js | Has session state - 
[task 2022-06-21T14:30:31.076Z] 14:30:31     INFO - Buffered messages finished
[task 2022-06-21T14:30:31.076Z] 14:30:31     INFO - TEST-UNEXPECTED-FAIL | devtools/client/framework/browser-toolbox/test/browser_browser_toolbox_netmonitor.js | Test timed out - 
[task 2022-06-21T14:30:31.076Z] 14:30:31     INFO - TEST-PASS | devtools/client/framework/browser-toolbox/test/browser_browser_toolbox_netmonitor.js | The main process DevToolsServer has no pending connection when the test ends - 

First occurrence: https://treeherder.mozilla.org/jobs?repo=autoland&searchStr=Linux%2C18.04%2Cx64%2CWebRender%2Copt%2CDevTools%2CMochitests%2Cwith%2CEFT%2Cwithout%2Cfission%2Cenabled%2Ctest-linux1804-64-qr%2Fopt-mochitest-devtools-chrome-dt-no-eft-nofis-e10s%2Cdt2&tochange=f91ee506e95a8db2dfa7da1fac11711e3ceaef36&fromchange=802e5ef4670f948fccb3bce4a02dc56bfce79a87&selectedTaskRun=VdDdf4c_SXeh67wlge4jUw.0
Nicolas, could this be related to changes in https://bugzilla.mozilla.org/show_bug.cgi?id=1764346?

Set release status flags based on info from the regressing bug 1583179

Could be a similar issue than Bug 1775274 , where we have unwanted requests being fired, messing up with the test

The test seemed to fail because the browsers was firing requests we weren't expecting.
To fix this, we set a few preferences that should prevent such requests to be made.

Backed out for causing failures on browser_browser_toolbox_print_preview.js.
FATAL ERROR: Non-local network connections are disabled and a connection attempt to firefox.settings.services.mozilla.com (18.65.229.79) was made

Push with failures

Failure log

Backout link

[task 2022-07-05T08:59:34.300Z] 08:59:34     INFO - TEST-START | devtools/client/framework/browser-toolbox/test/browser_browser_toolbox_print_preview.js
[task 2022-07-05T08:59:34.720Z] 08:59:34     INFO - GECKO(2352) | DevTools Server for Browser Toolbox listening on port: 46227
[task 2022-07-05T08:59:34.726Z] 08:59:34     INFO - GECKO(2352) | Starting Browser Toolbox /builds/worker/workspace/build/application/firefox/firefox-bin -no-remote -foreground -profile /tmp/tmps2384191.mozrunner/chrome_debugger_profile -chrome chrome://devtools/content/framework/browser-toolbox/window.html
[task 2022-07-05T08:59:34.870Z] 08:59:34     INFO - GECKO(2352) | [Parent 2352, Main Thread] WARNING: g_object_ref: assertion 'G_IS_OBJECT (object)' failed: 'glib warning', file /builds/worker/checkouts/gecko/toolkit/xre/nsSigHandlers.cpp:167
[task 2022-07-05T08:59:34.876Z] 08:59:34     INFO - GECKO(2352) | (firefox-nightly-autoland:2352): GLib-GObject-CRITICAL **: 08:59:34.874: g_object_ref: assertion 'G_IS_OBJECT (object)' failed
[task 2022-07-05T08:59:37.101Z] 08:59:37     INFO - GECKO(2352) | 3248> FATAL ERROR: Non-local network connections are disabled and a connection attempt to firefox.settings.services.mozilla.com (18.65.229.79) was made.
[task 2022-07-05T08:59:37.103Z] 08:59:37     INFO - GECKO(2352) | 3248> You should only access hostnames available via the test networking proxy (if running mochitests) or from a test-specific httpd.js server (if running xpcshell tests). Browser services should be disabled or redirected to a local server.
[task 2022-07-05T08:59:37.108Z] 08:59:37     INFO - GECKO(2352) | 3248> ExceptionHandler::GenerateDump cloned child 3319
[task 2022-07-05T08:59:37.109Z] 08:59:37     INFO - GECKO(2352) | 3248> ExceptionHandler::SendContinueSignalToChild sent continue signal to child
[task 2022-07-05T08:59:37.110Z] 08:59:37     INFO - GECKO(2352) | 3248> ExceptionHandler::WaitForContinueSignal waiting for continue signal...
[task 2022-07-05T08:59:37.398Z] 08:59:37     INFO - GECKO(2352) | JavaScript error: resource://gre/modules/subprocess/subprocess_common.jsm, line 129: uncaught exception: Object
[task 2022-07-05T09:02:34.311Z] 09:02:34     INFO - TEST-INFO | started process screentopng
[task 2022-07-05T09:02:34.912Z] 09:02:34     INFO - TEST-INFO | screentopng: exit 0
[task 2022-07-05T09:02:34.913Z] 09:02:34     INFO - Buffered messages logged at 08:59:34
[task 2022-07-05T09:02:34.914Z] 09:02:34     INFO - Entering test bound 
[task 2022-07-05T09:02:34.915Z] 09:02:34     INFO - Console message: [JavaScript Error: "uncaught exception: Object"]
[task 2022-07-05T09:02:34.916Z] 09:02:34     INFO - Adding a new tab with URL: data:text/html,<div id="test-div">PRINT PREVIEW TEST</div>
[task 2022-07-05T09:02:34.916Z] 09:02:34     INFO - Console message: [JavaScript Warning: "This page is in Quirks Mode. Page layout may be impacted. For Standards Mode use “<!DOCTYPE html>”." {file: "data:text/html,<div id="test-div">PRINT PREVIEW TEST</div>" line: 0}]
[task 2022-07-05T09:02:34.917Z] 09:02:34     INFO - Tab added and finished loading
[task 2022-07-05T09:02:34.917Z] 09:02:34     INFO - Start the print preview for the current tab
[task 2022-07-05T09:02:34.918Z] 09:02:34     INFO - Global property added while loading chrome://global/content/printUtils.js: SHOW_PAGE_SETUP_MENU
[task 2022-07-05T09:02:34.919Z] 09:02:34     INFO - Global property added while loading chrome://global/content/printUtils.js: PRINT_ALWAYS_SILENT
[task 2022-07-05T09:02:34.943Z] 09:02:34     INFO - Global property added while loading chrome://global/content/printUtils.js: PREFER_SYSTEM_DIALOG
[task 2022-07-05T09:02:34.944Z] 09:02:34     INFO - TEST-PASS | devtools/client/framework/browser-toolbox/test/browser_browser_toolbox_print_preview.js | Browser toolbox started - 
[task 2022-07-05T09:02:34.944Z] 09:02:34     INFO - TEST-PASS | devtools/client/framework/browser-toolbox/test/browser_browser_toolbox_print_preview.js | Has session state - 
[task 2022-07-05T09:02:34.945Z] 09:02:34     INFO - Buffered messages logged at 08:59:37
[task 2022-07-05T09:02:34.945Z] 09:02:34     INFO - Console message: [JavaScript Error: "uncaught exception: Object" {file: "resource://gre/modules/subprocess/subprocess_common.jsm" line: 129}]
[task 2022-07-05T09:02:34.946Z] 09:02:34     INFO - Buffered messages logged at 09:00:19
[task 2022-07-05T09:02:34.946Z] 09:02:34     INFO - Longer timeout required, waiting longer...  Remaining timeouts: 3
[task 2022-07-05T09:02:34.947Z] 09:02:34     INFO - Buffered messages logged at 09:01:04
[task 2022-07-05T09:02:34.947Z] 09:02:34     INFO - Longer timeout required, waiting longer...  Remaining timeouts: 2
[task 2022-07-05T09:02:34.948Z] 09:02:34     INFO - Buffered messages logged at 09:01:49
[task 2022-07-05T09:02:34.948Z] 09:02:34     INFO - Longer timeout required, waiting longer...  Remaining timeouts: 1
[task 2022-07-05T09:02:34.949Z] 09:02:34     INFO - Buffered messages finished
[task 2022-07-05T09:02:34.949Z] 09:02:34     INFO - TEST-UNEXPECTED-FAIL | devtools/client/framework/browser-toolbox/test/browser_browser_toolbox_print_preview.js | Test timed out - 
[task 2022-07-05T09:02:34.950Z] 09:02:34     INFO - Removing tab.
[task 2022-07-05T09:02:34.951Z] 09:02:34     INFO - Waiting for event: 'TabClose' on [object XULElement].
[task 2022-07-05T09:02:34.952Z] 09:02:34     INFO - Got event: 'TabClose' on [object XULElement].
[task 2022-07-05T09:02:34.952Z] 09:02:34     INFO - Tab removed and finished closing
[task 2022-07-05T09:02:34.953Z] 09:02:34     INFO - TEST-PASS | devtools/client/framework/browser-toolbox/test/browser_browser_toolbox_print_preview.js | The main process DevToolsServer has no pending connection when the test ends - 
[task 2022-07-05T09:02:34.956Z] 09:02:34     INFO - GECKO(2352) | MEMORY STAT | vsize 3436MB | residentFast 576MB | heapAllocated 317MB
[task 2022-07-05T09:02:34.960Z] 09:02:34     INFO - TEST-OK | devtools/client/framework/browser-toolbox/test/browser_browser_toolbox_print_preview.js | took 180142ms
[task 2022-07-05T09:02:34.961Z] 09:02:34     INFO - checking window state
[task 2022-07-05T09:02:34.962Z] 09:02:34     INFO - TEST-START | devtools/client/framework/browser-toolbox/test/browser_browser_toolbox_rtl.js

https://hg.mozilla.org/mozilla-central/rev/31339d0d49f1