Bug: Intermittent browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | Uncaught exception - at /components/places/tests/browser/browser_bug631374_tags_selector_scroll.js:9 - TypeError: item is undefined
Status: RESOLVED
Priority: P5
Resolution: INCOMPLETE
Created: 2021-04-21 11:24:29+00:00
Resolved: 2021-05-25 17:05:29+00:00

**Filed by:** malexandru [at] mozilla.com
**Parsed log:** https://treeherder.mozilla.org/logviewer?job_id=337252033&repo=mozilla-beta
**Full log:** https://firefox-ci-tc.services.mozilla.com/api/queue/v1/task/ZKi7XGd4RBiRxF1jBTjetQ/runs/0/artifacts/public/logs/live_backing.log

---
```
[task 2021-04-21T03:38:43.159Z] 03:38:43     INFO - TEST-START | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js
[task 2021-04-21T03:38:43.340Z] 03:38:43     INFO - GECKO(6894) | Waiting for browser load
[task 2021-04-21T03:38:43.341Z] 03:38:43     INFO - GECKO(6894) | Waiting for browser state change
[task 2021-04-21T03:38:43.348Z] 03:38:43     INFO - GECKO(6894) | Saw state 110001 and status 0
[task 2021-04-21T03:38:43.369Z] 03:38:43     INFO - GECKO(6894) | Saw state c0010 and status 0
[task 2021-04-21T03:38:43.370Z] 03:38:43     INFO - GECKO(6894) | Browser got expected state change about:buildconfig
[task 2021-04-21T03:38:43.970Z] 03:38:43     INFO - TEST-INFO | started process screentopng
[task 2021-04-21T03:38:44.332Z] 03:38:44     INFO - TEST-INFO | screentopng: exit 0
[task 2021-04-21T03:38:44.333Z] 03:38:44     INFO - Buffered messages logged at 03:38:43
[task 2021-04-21T03:38:44.333Z] 03:38:44     INFO - Entering test bound 
[task 2021-04-21T03:38:44.334Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | gEditItemOverlay is in context - 
[task 2021-04-21T03:38:44.334Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | gEditItemOverlay is initialized - 
[task 2021-04-21T03:38:44.335Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | Valid listItem found - 
[task 2021-04-21T03:38:44.335Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | Item is checked 8 - 
[task 2021-04-21T03:38:44.336Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | Scroll position did not change - 
[task 2021-04-21T03:38:44.336Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | Valid new listItem found - 
[task 2021-04-21T03:38:44.336Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | New listItem is unchecked 8 - 
[task 2021-04-21T03:38:44.336Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | Correct tag is still selected - 
[task 2021-04-21T03:38:44.337Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | Scroll position did not change - 
[task 2021-04-21T03:38:44.337Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | Valid listItem found - 
[task 2021-04-21T03:38:44.337Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | Item is checked 10 - 
[task 2021-04-21T03:38:44.338Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | Scroll position did not change - 
[task 2021-04-21T03:38:44.338Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | Valid new listItem found - 
[task 2021-04-21T03:38:44.339Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | New listItem is unchecked 10 - 
[task 2021-04-21T03:38:44.339Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | Correct tag is still selected - 
[task 2021-04-21T03:38:44.339Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | Scroll position did not change - 
[task 2021-04-21T03:38:44.340Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | Valid listItem found - 
[task 2021-04-21T03:38:44.341Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | Item is checked 12 - 
[task 2021-04-21T03:38:44.341Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | Scroll position did not change - 
[task 2021-04-21T03:38:44.341Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | Valid new listItem found - 
[task 2021-04-21T03:38:44.345Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | New listItem is unchecked 12 - 
[task 2021-04-21T03:38:44.346Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | Correct tag is still selected - 
[task 2021-04-21T03:38:44.346Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | Scroll position did not change - 
[task 2021-04-21T03:38:44.346Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | Valid listItem found - 
[task 2021-04-21T03:38:44.347Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | Item is checked 13 - 
[task 2021-04-21T03:38:44.348Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | Scroll position is correct - 
[task 2021-04-21T03:38:44.348Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | Valid new listItem found - 
[task 2021-04-21T03:38:44.349Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | New listItem is checked 13 - 
[task 2021-04-21T03:38:44.349Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | The next tag is now selected - 
[task 2021-04-21T03:38:44.349Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | Valid listItem found - 
[task 2021-04-21T03:38:44.349Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | Item is checked 11 - 
[task 2021-04-21T03:38:44.349Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | Scroll position is correct - 
[task 2021-04-21T03:38:44.350Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | Valid new listItem found - 
[task 2021-04-21T03:38:44.351Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | New listItem is checked 11 - 
[task 2021-04-21T03:38:44.351Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | The next tag is now selected - 
[task 2021-04-21T03:38:44.351Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | Valid listItem found - 
[task 2021-04-21T03:38:44.351Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | Item is checked 9 - 
[task 2021-04-21T03:38:44.352Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | Scroll position is correct - 
[task 2021-04-21T03:38:44.352Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | Valid new listItem found - 
[task 2021-04-21T03:38:44.352Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | New listItem is checked 9 - 
[task 2021-04-21T03:38:44.355Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | The next tag is now selected - 
[task 2021-04-21T03:38:44.355Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | Valid listItem found - 
[task 2021-04-21T03:38:44.356Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | Item is checked 7 - 
[task 2021-04-21T03:38:44.356Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | Scroll position is correct - 
[task 2021-04-21T03:38:44.357Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | Valid new listItem found - 
[task 2021-04-21T03:38:44.358Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | New listItem is checked 7 - 
[task 2021-04-21T03:38:44.358Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | The next tag is now selected - 
[task 2021-04-21T03:38:44.359Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | Valid listItem found - 
[task 2021-04-21T03:38:44.360Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | Item is checked 5 - 
[task 2021-04-21T03:38:44.360Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | Scroll position is correct - 
[task 2021-04-21T03:38:44.361Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | Valid new listItem found - 
[task 2021-04-21T03:38:44.361Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | New listItem is checked 5 - 
[task 2021-04-21T03:38:44.362Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | The next tag is now selected - 
[task 2021-04-21T03:38:44.363Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | Valid listItem found - 
[task 2021-04-21T03:38:44.363Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | Item is checked 3 - 
[task 2021-04-21T03:38:44.364Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | Scroll position is correct - 
[task 2021-04-21T03:38:44.364Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | Valid new listItem found - 
[task 2021-04-21T03:38:44.366Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | New listItem is checked 3 - 
[task 2021-04-21T03:38:44.367Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | The next tag is now selected - 
[task 2021-04-21T03:38:44.367Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | Valid listItem found - 
[task 2021-04-21T03:38:44.368Z] 03:38:44     INFO - TEST-PASS | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | Item is checked 1 - 
[task 2021-04-21T03:38:44.369Z] 03:38:44     INFO - Buffered messages finished
[task 2021-04-21T03:38:44.369Z] 03:38:44     INFO - TEST-UNEXPECTED-FAIL | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | Uncaught exception - at chrome://mochitests/content/browser/browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js:9 - TypeError: item is undefined
[task 2021-04-21T03:38:44.370Z] 03:38:44     INFO - Stack trace:
[task 2021-04-21T03:38:44.370Z] 03:38:44     INFO - scrolledIntoView@chrome://mochitests/content/browser/browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js:9:18
[task 2021-04-21T03:38:44.371Z] 03:38:44     INFO - @chrome://mochitests/content/browser/browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js:148:8
[task 2021-04-21T03:38:44.371Z] 03:38:44     INFO - Leaving test bound 
[task 2021-04-21T03:38:44.372Z] 03:38:44     INFO - GECKO(6894) | MEMORY STAT | vsize 3504MB | residentFast 550MB | heapAllocated 265MB
[task 2021-04-21T03:38:44.373Z] 03:38:44     INFO - TEST-OK | browser/components/places/tests/browser/browser_bug631374_tags_selector_scroll.js | took 941ms
[task 2021-04-21T03:38:44.373Z] 03:38:44     INFO - checking window state
[task 2021-04-21T03:38:44.374Z] 03:38:44     INFO - TEST-START | browser/components/places/tests/browser/browser_check_correct_controllers.js```