Because of the presence of this line in some logs: https://treeherder.mozilla.org/logviewer?job_id=387281402&repo=mozilla-central&lineNumber=2479 I suspect it's from Bug 1781046. Unfortunately can't confirm that backout on try because it doesn't timeout there, it does only on central. Might a combination of test groups involved in this.
Bug 1784591 Comment 6 Edit History
Note: The actual edited comment in the bug view page will always show the original commenter’s name and original timestamp.
Because of the presence of this line in some logs: https://treeherder.mozilla.org/logviewer?job_id=387281402&repo=mozilla-central&lineNumber=2479 I suspect it's from Bug 1781046. Unfortunately can't confirm that backout on try because it doesn't timeout there, it does only on central. Might be a combination of test groups involved in this.