Filed by: nbeleuzu [at] mozilla.com
Parsed log: https://treeherder.mozilla.org/logviewer?job_id=320326183&repo=autoland
Full log: https://firefox-ci-tc.services.mozilla.com/api/queue/v1/task/GtivKbwIRm6TD67AA637iQ/runs/0/artifacts/public/logs/live_backing.log

[task 2020-10-31T01:13:29.996Z] 01:13:29     INFO - Console message: [JavaScript Warning: "Loading failed for the <script> with source “resource://devtools-client-shared/components/tabs/Tabs.js”." {file: "http://example.com/browser/docshell/test/browser/file_bug1673702.json" line: 1}]
[task 2020-10-31T01:13:29.998Z] 01:13:29     INFO - Console message: [JavaScript Error: "Error: Script error for: devtools/client/shared/components/tabs/Tabs
[task 2020-10-31T01:13:29.999Z] 01:13:29     INFO - http://requirejs.org/docs/errors.html#scripterror" {file: "resource://devtools-client-jsonview/lib/require.js" line: 170}]
[task 2020-10-31T01:13:29.999Z] 01:13:29     INFO - makeError@resource://devtools-client-jsonview/lib/require.js:170:17
[task 2020-10-31T01:13:29.999Z] 01:13:29     INFO - onScriptError@resource://devtools-client-jsonview/lib/require.js:1693:36
[task 2020-10-31T01:13:30.000Z] 01:13:30     INFO - 
[task 2020-10-31T01:13:30.001Z] 01:13:30     INFO - Console message: [JavaScript Error: "NS_ERROR_NOT_AVAILABLE: Component returned failure code: 0x80040111 (NS_ERROR_NOT_AVAILABLE) [nsIChannel.contentType]" {file: "resource://devtools/client/jsonview/Sniffer.jsm" line: 53}]
[task 2020-10-31T01:13:30.001Z] 01:13:30     INFO - getMIMETypeFromContent@resource://devtools/client/jsonview/Sniffer.jsm:53:13
[task 2020-10-31T01:13:30.001Z] 01:13:30     INFO - 
[task 2020-10-31T01:13:30.001Z] 01:13:30     INFO - Buffered messages finished
[task 2020-10-31T01:13:30.002Z] 01:13:30     INFO - TEST-UNEXPECTED-FAIL | docshell/test/browser/browser_bug1673702.js | undefined assertion name - Got "http://example.com/browser/docshell/test/browser/file_bug1673702.json", expected "http://example.org/browser/docshell/test/browser/dummy_page.html"
[task 2020-10-31T01:13:30.002Z] 01:13:30     INFO - Stack trace:
[task 2020-10-31T01:13:30.002Z] 01:13:30     INFO - chrome://mochikit/content/browser-test.js:test_is:1332
[task 2020-10-31T01:13:30.002Z] 01:13:30     INFO - chrome://mochitests/content/browser/docshell/test/browser/browser_bug1673702.js:test_backAndReload/<:22
[task 2020-10-31T01:13:30.005Z] 01:13:30     INFO - Leaving test bound test_backAndReload
[task 2020-10-31T01:13:30.005Z] 01:13:30     INFO - GECKO(6392) | [Parent 6392, Main Thread] WARNING: Not implemented in the parent process!: file /builds/worker/checkouts/gecko/docshell/shistory/SessionHistoryEntry.cpp:503
[task 2020-10-31T01:13:30.006Z] 01:13:30     INFO - GECKO(6392) | [Parent 6392, Main Thread] WARNING: Not implemented in the parent process!: file /builds/worker/checkouts/gecko/docshell/shistory/SessionHistoryEntry.cpp:503
[task 2020-10-31T01:13:30.006Z] 01:13:30     INFO - GECKO(6392) | MEMORY STAT | vsize 3109MB | residentFast 400MB | heapAllocated 129MB
[task 2020-10-31T01:13:30.007Z] 01:13:30     INFO - TEST-OK | docshell/test/browser/browser_bug1673702.js | took 1610ms
[task 2020-10-31T01:13:30.012Z] 01:13:30     INFO - GECKO(6392) | [Child 6565: Main Thread]: I/DocShellAndDOMWindowLeak ++DOCSHELL 0x7fda887a9000 == 2 [pid = 6565] [id = 32]
[task 2020-10-31T01:13:30.013Z] 01:13:30     INFO - GECKO(6392) | [Child 6565: Main Thread]: I/DocShellAndDOMWindowLeak ++DOMWINDOW == 8 (0x7fda887d2580) [pid = 6565] [serial = 55] [outer = (nil)]
[task 2020-10-31T01:13:30.014Z] 01:13:30     INFO - GECKO(6392) | [Child 6565: Main Thread]: I/DocShellAndDOMWindowLeak ++DOMWINDOW == 9 (0x7fda887ab400) [pid = 6565] [serial = 56] [outer = 0x7fda887d2580]
[task 2020-10-31T01:13:30.015Z] 01:13:30     INFO - checking window state```