Filed by: csabou [at] mozilla.com
Parsed log: https://treeherder.mozilla.org/logviewer.html#?job_id=282054847&repo=mozilla-central
Full log: https://firefox-ci-tc.services.mozilla.com/api/queue/v1/task/GoxkAUjKQ6C2x21CPCDx6w/runs/0/artifacts/public/logs/live_backing.log

[task 2019-12-20T05:54:31.521Z] 05:54:31 INFO - TEST-PASS | devtools/client/debugger/test/mochitest/browser_dbg-watchpoints.js | Frame paused at 25, but expected 25 -
[task 2019-12-20T05:54:31.521Z] 05:54:31 INFO - Buffered messages finished
[task 2019-12-20T05:54:31.522Z] 05:54:31 INFO - TEST-UNEXPECTED-FAIL | devtools/client/debugger/test/mochitest/browser_dbg-watchpoints.js | A promise chain failed to handle a rejection: A mutation operation in the transaction failed because a constraint was not satisfied. - stack: setItemOnError@resource://devtools/shared/async-storage.js:110:17
[task 2019-12-20T05:54:31.522Z] 05:54:31 INFO - EventHandlerNonNullsetItem/</<@resource://devtools/shared/async-storage.js:108:9
[task 2019-12-20T05:54:31.522Z] 05:54:31 INFO - withStore@resource://devtools/shared/async-storage.js:58:14
[task 2019-12-20T05:54:31.522Z] 05:54:31 INFO - setItem/<@resource://devtools/shared/async-storage.js:103:14
[task 2019-12-20T05:54:31.523Z] 05:54:31 INFO - setItem@resource://devtools/shared/async-storage.js:102:10
[task 2019-12-20T05:54:31.523Z] 05:54:31 INFO - set@resource://devtools/client/shared/async-store-helper.js:38:29
[task 2019-12-20T05:54:31.523Z] 05:54:31 INFO - set@resource://devtools/client/shared/async-store-helper.js:49:15
[task 2019-12-20T05:54:31.523Z] 05:54:31 INFO - updatePrefs@resource://devtools/client/debugger/src/utils/bootstrap.js:160:5
[task 2019-12-20T05:54:31.523Z] 05:54:31 INFO - bootstrapStore/<@resource://devtools/client/debugger/src/utils/bootstrap.js:88:36
[task 2019-12-20T05:54:31.523Z] 05:54:31 INFO - dispatch@resource://devtools/client/shared/vendor/redux.js:416:7
[task 2019-12-20T05:54:31.523Z] 05:54:31 INFO - log/</<@resource://devtools/client/debugger/src/actions/utils/middleware/log.js:114:9
[task 2019-12-20T05:54:31.524Z] 05:54:31 INFO - waitUntilService/</<@resource://devtools/client/debugger/src/actions/utils/middleware/wait-service.js:71:24
[task 2019-12-20T05:54:31.524Z] 05:54:31 INFO - promiseMiddleware/</<@resource://devtools/client/debugger/src/actions/utils/middleware/promise.js:46:14
[task 2019-12-20T05:54:31.524Z] 05:54:31 INFO - context/</<@resource://devtools/client/debugger/src/actions/utils/middleware/context.js:35:12
[task 2019-12-20T05:54:31.524Z] 05:54:31 INFO - thunk/</</<@resource://devtools/client/debugger/src/actions/utils/middleware/thunk.js:29:100
[task 2019-12-20T05:54:31.525Z] 05:54:31 INFO - dispatch@resource://devtools/client/shared/vendor/redux.js:755:18
[task 2019-12-20T05:54:31.525Z] 05:54:31 INFO - getEventListenerBreakpointTypes/<@resource://devtools/client/debugger/src/actions/event-listeners.js:102:13
[task 2019-12-20T05:54:31.525Z] 05:54:31 INFO - asyncthunk/</</<@resource://devtools/client/debugger/src/actions/utils/middleware/thunk.js:29:45
[task 2019-12-20T05:54:31.525Z] 05:54:31 INFO - bindActionCreator/<@resource://devtools/client/shared/vendor/redux.js:644:12
[task 2019-12-20T05:54:31.525Z] 05:54:31 INFO - onConnect@resource://devtools/client/debugger/src/client/firefox.js:61:11
[task 2019-12-20T05:54:31.526Z] 05:54:31 INFO - asynconConnect@resource://devtools/client/debugger/src/client/index.js:84:28
[task 2019-12-20T05:54:31.526Z] 05:54:31 INFO - asyncbootstrap@resource://devtools/client/debugger/src/main.js:28:31
[task 2019-12-20T05:54:31.527Z] 05:54:31 INFO - open@resource://devtools/client/debugger/panel.js:45:38
[task 2019-12-20T05:54:31.527Z] 05:54:31 INFO - onLoad@resource://devtools/client/framework/toolbox.js:2455:27
[task 2019-12-20T05:54:31.527Z] 05:54:31 INFO - Rejection date: Fri Dec 20 2019 05:54:18 GMT+0000 (Coordinated Universal Time) - false == true - JS frame :: resource://testing-common/PromiseTestUtils.jsm :: assertNoUncaughtRejections :: line 265
[task 2019-12-20T05:54:31.527Z] 05:54:31 INFO - Stack trace:
[task 2019-12-20T05:54:31.528Z] 05:54:31 INFO - resource://testing-common/PromiseTestUtils.jsm:assertNoUncaughtRejections:265
[task 2019-12-20T05:54:31.528Z] 05:54:31 INFO - chrome://mochikit/content/browser-test.js:Tester_execTest/<:1093
[task 2019-12-20T05:54:31.528Z] 05:54:31 INFO - chrome://mochikit/content/browser-test.js:Tester_execTest:1097
[task 2019-12-20T05:54:31.529Z] 05:54:31 INFO - chrome://mochikit/content/browser-test.js:nextTest/<:925
[task 2019-12-20T05:54:31.529Z] 05:54:31 INFO - chrome://mochikit/content/tests/SimpleTest/SimpleTest.js:SimpleTest.waitForFocus/waitForFocusInner/focusedOrLoaded/<:808
[task 2019-12-20T05:54:31.530Z] 05:54:31 INFO - Not taking screenshot here: see the one that was previously logged

This permafailing on TC jobs since Bug 1602804 https://hg.mozilla.org/mozilla-central/rev/0cc5dce6603393d3e94a419861c03c44563a6bd7 got into central. Jaril, could you please take a look over it?
https://treeherder.mozilla.org/#/jobs?repo=mozilla-central&group_state=expanded&searchStr=linux%2Cx64%2Cccov%2Copt%2Ctest-linux64-ccov%2Fopt-test-coverage-e10s%2C%28tc%29&revision=c8ce8b91465a7192b056102481d633fef850fac6&selectedJob=282054847

No failure in 2 years, test is only disabled in debug (not related to this intermittent) clearing the ni.

https://wiki.mozilla.org/Bug_Triage#Intermittent_Test_Failure_Cleanup
For more information, please visit auto_nag documentation.