Bug: Intermittent browser/components/newtab/test/browser/browser_aboutwelcome_observer.js | leaked 2 window(s) until shutdown [url = about:blank]
Status: RESOLVED
Priority: P5
Resolution: INCOMPLETE
Created: 2021-08-26 23:46:05+00:00
Resolved: 2023-10-25 12:04:41+00:00

**Filed by:** malexandru [at] mozilla.com
**Parsed log:** https://treeherder.mozilla.org/logviewer?job_id=349717439&repo=mozilla-central
**Full log:** https://firefox-ci-tc.services.mozilla.com/api/queue/v1/task/fMSmFmjPQc6g9dcHibbg0A/runs/0/artifacts/public/logs/live_backing.log

---
```
[task 2021-08-26T22:21:27.461Z] 22:21:27     INFO - GECKO(6408) | [GPU 1792, Main Thread] WARNING: NS_ENSURE_TRUE(Preferences::InitStaticMembers()) failed: file /builds/worker/checkouts/gecko/modules/libpref/Preferences.cpp:4438
[task 2021-08-26T22:21:28.196Z] 22:21:28     INFO - GECKO(6408) | [Parent 2152: Main Thread]: I/DocShellAndDOMWindowLeak --DOMWINDOW == 9 (2a152070000) [pid = 2152] [serial = 4] [outer = 0] [url = about:blank]
[task 2021-08-26T22:21:28.200Z] 22:21:28     INFO - GECKO(6408) | [Parent 2152: Main Thread]: I/DocShellAndDOMWindowLeak --DOMWINDOW == 8 (2a1455d1e40) [pid = 2152] [serial = 3] [outer = 0] [url = chrome://browser/content/browser.xhtml]
[task 2021-08-26T22:21:28.201Z] 22:21:28     INFO - GECKO(6408) | [Parent 2152: Main Thread]: I/DocShellAndDOMWindowLeak --DOMWINDOW == 7 (2a15c290740) [pid = 2152] [serial = 12] [outer = 0] [url = chrome://mochikit/content/browser-harness.xhtml]
[task 2021-08-26T22:21:28.202Z] 22:21:28     INFO - GECKO(6408) | [Parent 2152: Main Thread]: I/DocShellAndDOMWindowLeak --DOMWINDOW == 6 (2a15a862c00) [pid = 2152] [serial = 13] [outer = 0] [url = about:blank]
[task 2021-08-26T22:21:28.202Z] 22:21:28     INFO - GECKO(6408) | [Parent 2152: Main Thread]: I/DocShellAndDOMWindowLeak --DOMWINDOW == 5 (2a1559e6200) [pid = 2152] [serial = 5] [outer = 0] [url = chrome://extensions/content/dummy.xhtml]
[task 2021-08-26T22:21:28.203Z] 22:21:28     INFO - GECKO(6408) | [Parent 2152: Main Thread]: I/DocShellAndDOMWindowLeak --DOMWINDOW == 4 (2a157ccac00) [pid = 2152] [serial = 6] [outer = 0] [url = chrome://extensions/content/dummy.xhtml]
[task 2021-08-26T22:21:28.204Z] 22:21:28     INFO - GECKO(6408) | [Parent 2152: Main Thread]: I/DocShellAndDOMWindowLeak --DOMWINDOW == 3 (2a153db3200) [pid = 2152] [serial = 9] [outer = 0] [url = resource://gre-resources/hiddenWindow.html]
[task 2021-08-26T22:21:28.204Z] 22:21:28     INFO - GECKO(6408) | [Parent 2152: Main Thread]: I/DocShellAndDOMWindowLeak --DOMWINDOW == 2 (2a145543000) [pid = 2152] [serial = 44] [outer = 0] [url = about:blank]
[task 2021-08-26T22:21:28.204Z] 22:21:28     INFO - GECKO(6408) | [Parent 2152: Main Thread]: I/DocShellAndDOMWindowLeak --DOMWINDOW == 1 (2a15741a040) [pid = 2152] [serial = 7] [outer = 0] [url = about:blank]
[task 2021-08-26T22:21:28.207Z] 22:21:28     INFO - GECKO(6408) | [Parent 2152: Main Thread]: I/DocShellAndDOMWindowLeak --DOMWINDOW == 0 (2a1580f1c00) [pid = 2152] [serial = 11] [outer = 0] [url = resource://gre-resources/hiddenWindow.html]
[task 2021-08-26T22:21:28.219Z] 22:21:28     INFO - GECKO(6408) | [Parent 2152, Main Thread] WARNING: Extra shutdown CC: 'i < NORMAL_SHUTDOWN_COLLECTIONS', file /builds/worker/checkouts/gecko/xpcom/base/nsCycleCollector.cpp:3357
[task 2021-08-26T22:21:28.278Z] 22:21:28     INFO - GECKO(6408) | [Parent 2152, Main Thread] WARNING: NS_ENSURE_TRUE(Preferences::InitStaticMembers()) failed: file /builds/worker/checkouts/gecko/modules/libpref/Preferences.cpp:4438
[task 2021-08-26T22:21:28.343Z] 22:21:28     INFO - TEST-INFO | Main app process: exit 0
[task 2021-08-26T22:21:28.344Z] 22:21:28     INFO - TEST-INFO | Confirming we saw 197 DOCSHELL created and 197 destroyed log strings.
[task 2021-08-26T22:21:28.344Z] 22:21:28     INFO - TEST-INFO | Confirming we saw 538 DOMWINDOW created and 538 destroyed log strings.
[task 2021-08-26T22:21:28.345Z] 22:21:28    ERROR - TEST-UNEXPECTED-FAIL | browser/components/newtab/test/browser/browser_aboutwelcome_observer.js | leaked 2 window(s) until shutdown [url = about:blank]
[task 2021-08-26T22:21:28.346Z] 22:21:28     INFO - TEST-INFO | browser/components/newtab/test/browser/browser_aboutwelcome_observer.js | windows(s) leaked: [pid = 7164] [serial = 2], [pid = 7164] [serial = 1]
[task 2021-08-26T22:21:28.346Z] 22:21:28    ERROR - TEST-UNEXPECTED-FAIL | browser/components/newtab/test/browser/browser_aboutwelcome_observer.js | leaked 1 docShell(s) until shutdown
[task 2021-08-26T22:21:28.347Z] 22:21:28     INFO - TEST-INFO | browser/components/newtab/test/browser/browser_aboutwelcome_observer.js | docShell(s) leaked: [pid = 7164] [id = 0]
[task 2021-08-26T22:21:28.347Z] 22:21:28     INFO - TEST-INFO | browser/components/newtab/test/browser/browser_aboutwelcome_observer.js | This test created 1 hidden window(s)
[task 2021-08-26T22:21:28.347Z] 22:21:28     INFO - TEST-INFO | browser/components/newtab/test/browser/browser_aboutwelcome_observer.js | This test created 1 hidden docshell(s)
[task 2021-08-26T22:21:28.348Z] 22:21:28     INFO - TEST-INFO | browser/components/newtab/test/browser/browser_aboutwelcome_attribution.js | This test created 1 hidden window(s)
[task 2021-08-26T22:21:28.348Z] 22:21:28     INFO - TEST-INFO | browser/components/newtab/test/browser/browser_aboutwelcome_attribution.js | This test created 1 hidden docshell(s)
[task 2021-08-26T22:21:28.349Z] 22:21:28     INFO - TEST-INFO | browser/components/newtab/test/browser/browser_aboutwelcome_focus.js | This test created 1 hidden window(s)
[task 2021-08-26T22:21:28.349Z] 22:21:28     INFO - TEST-INFO | browser/components/newtab/test/browser/browser_aboutwelcome_focus.js | This test created 1 hidden docshell(s)
[task 2021-08-26T22:21:28.350Z] 22:21:28     INFO - TEST-INFO | browser/components/newtab/test/browser/browser_aboutwelcome_multistage_default.js | This test created 1 hidden window(s)
[task 2021-08-26T22:21:28.350Z] 22:21:28     INFO - TEST-INFO | browser/components/newtab/test/browser/browser_aboutwelcome_multistage_default.js | This test created 1 hidden docshell(s)
[task 2021-08-26T22:21:28.351Z] 22:21:28     INFO - TEST-INFO | browser/components/newtab/test/browser/browser_aboutwelcome_multistage_experimentAPI.js | This test created 1 hidden window(s)
[task 2021-08-26T22:21:28.351Z] 22:21:28     INFO - TEST-INFO | browser/components/newtab/test/browser/browser_aboutwelcome_multistage_experimentAPI.js | This test created 1 hidden docshell(s)
[task 2021-08-26T22:21:28.352Z] 22:21:28     INFO - TEST-INFO | browser/components/newtab/test/browser/browser_aboutwelcome_multistage_primary.js | This test created 1 hidden window(s)
[task 2021-08-26T22:21:28.352Z] 22:21:28     INFO - TEST-INFO | browser/components/newtab/test/browser/browser_aboutwelcome_multistage_primary.js | This test created 1 hidden docshell(s)
[task 2021-08-26T22:21:28.352Z] 22:21:28     INFO - TEST-INFO | browser/components/newtab/test/browser/browser_aboutwelcome_rtamo.js | This test created 1 hidden window(s)
[task 2021-08-26T22:21:28.353Z] 22:21:28     INFO - TEST-INFO | browser/components/newtab/test/browser/browser_aboutwelcome_rtamo.js | This test created 1 hidden docshell(s)
[task 2021-08-26T22:21:28.353Z] 22:21:28     INFO - TEST-INFO | browser/components/newtab/test/browser/browser_as_load_location.js | This test created 1 hidden window(s)
[task 2021-08-26T22:21:28.354Z] 22:21:28     INFO - TEST-INFO | browser/components/newtab/test/browser/browser_as_load_location.js | This test created 1 hidden docshell(s)
[task 2021-08-26T22:21:28.354Z] 22:21:28     INFO - TEST-INFO | browser/components/newtab/test/browser/browser_as_render.js | This test created 1 hidden window(s)
[task 2021-08-26T22:21:28.355Z] 22:21:28     INFO - TEST-INFO | browser/components/newtab/test/browser/browser_as_render.js | This test created 1 hidden docshell(s)
[task 2021-08-26T22:21:28.355Z] 22:21:28     INFO - TEST-INFO | browser/components/newtab/test/browser/browser_asrouter_cfr.js | This test created 1 hidden window(s)
[task 2021-08-26T22:21:28.356Z] 22:21:28     INFO - TEST-INFO | browser/components/newtab/test/browser/browser_asrouter_cfr.js | This test created 1 hidden docshell(s)
[task 2021-08-26T22:21:28.356Z] 22:21:28     INFO - TEST-INFO | browser/components/newtab/test/browser/browser_asrouter_infobar.js | This test created 1 hidden window(s)
[task 2021-08-26T22:21:28.356Z] 22:21:28     INFO - TEST-INFO | browser/components/newtab/test/browser/browser_asrouter_infobar.js | This test created 1 hidden docshell(s)
[task 2021-08-26T22:21:28.357Z] 22:21:28     INFO - TEST-INFO | browser/components/newtab/test/browser/browser_asrouter_snippets.js | This test created 1 hidden window(s)
[task 2021-08-26T22:21:28.357Z] 22:21:28     INFO - TEST-INFO | browser/components/newtab/test/browser/browser_asrouter_snippets.js | This test created 1 hidden docshell(s)
[task 2021-08-26T22:21:28.358Z] 22:21:28     INFO - TEST-INFO | browser/components/newtab/test/browser/browser_asrouter_snippets_dismiss.js | This test created 1 hidden window(s)
[task 2021-08-26T22:21:28.358Z] 22:21:28     INFO - TEST-INFO | browser/components/newtab/test/browser/browser_asrouter_snippets_dismiss.js | This test created 1 hidden docshell(s)
[task 2021-08-26T22:21:28.359Z] 22:21:28     INFO - TEST-INFO | browser/components/newtab/test/browser/browser_asrouter_targeting.js | This test created 1 hidden window(s)
[task 2021-08-26T22:21:28.359Z] 22:21:28     INFO - TEST-INFO | browser/components/newtab/test/browser/browser_asrouter_targeting.js | This test created 1 hidden docshell(s)
[task 2021-08-26T22:21:28.359Z] 22:21:28     INFO - TEST-INFO | browser/components/newtab/test/browser/browser_asrouter_toolbarbadge.js | This test created 1 hidden window(s)
[task 2021-08-26T22:21:28.360Z] 22:21:28     INFO - TEST-INFO | browser/components/newtab/test/browser/browser_asrouter_toolbarbadge.js | This test created 1 hidden docshell(s)
[task 2021-08-26T22:21:28.360Z] 22:21:28     INFO - TEST-INFO | browser/components/newtab/test/browser/browser_context_menu_item.js | This test created 1 hidden window(s)
[task 2021-08-26T22:21:28.361Z] 22:21:28     INFO - TEST-INFO | browser/components/newtab/test/browser/browser_context_menu_item.js | This test created 1 hidden docshell(s)
[task 2021-08-26T22:21:28.361Z] 22:21:28     INFO - TEST-INFO | browser/components/newtab/test/browser/browser_customize_menu_content.js | This test created 1 hidden window(s)
[task 2021-08-26T22:21:28.361Z] 22:21:28     INFO - TEST-INFO | browser/components/newtab/test/browser/browser_customize_menu_content.js | This test created 1 hidden docshell(s)
[task 2021-08-26T22:21:28.362Z] 22:21:28     INFO - TEST-INFO | browser/components/newtab/test/browser/browser_customize_menu_render.js | This test created 1 hidden window(s)
[task 2021-08-26T22:21:28.362Z] 22:21:28     INFO - TEST-INFO | browser/components/newtab/test/browser/browser_customize_menu_render.js | This test created 1 hidden docshell(s)
[task 2021-08-26T22:21:28.363Z] 22:21:28     INFO - TEST-INFO | browser/components/newtab/test/browser/browser_discovery_card.js | This test created 1 hidden window(s)
```