Bug: C-C TB, local mochitest, strange error, Invalid ETag "undefined"  store@resource://services-settings/SyncHistory.jsm:52:13
Status: NEW
Priority: --
Created: 2022-12-12 03:07:52+00:00
Resolved: 2023-01-04 01:26:11+00:00

While running TB mochitest by executing FULL DEBUG version of C-C TB, I get the following error (for quite some time).
```
05:32.03 INFO Console message: [JavaScript Error: "Invalid ETag value "undefined"" {file: "resource://services-settings/SyncHistory.jsm" line: 52}]
store@resource://services-settings/SyncHistory.jsm:52:13
editAttendees@chrome://calendar/content/calendar-item-iframe.js:1987:13
receiveMessage@chrome://calendar/content/calendar-item-iframe.js:252:7
```

I have no idea why this happens.

I see the same error (presumably in an optimized binary test) as follows. The third line quoted below.

From: https://firefoxci.taskcluster-artifacts.net/S8NYBBWRSHOV-HcqVVQfLg/0/public/logs/live_backing.log

```
[task 2022-12-10T00:25:58.060Z] 00:25:58     INFO - checking window state
[task 2022-12-10T00:25:58.062Z] 00:25:58     INFO - TEST-START | comm/calendar/test/browser/invitations/browser_imipBarRepeatUpdates.js
[task 2022-12-10T00:26:00.531Z] 00:26:00     INFO - GECKO(3008) | console.error: (new Error("Invalid ETag value \"undefined\"", "resource://services-settings/SyncHistory.jsm", 52))
[task 2022-12-10T00:27:34.264Z] 00:27:34     INFO - GECKO(3008) | MEMORY STAT | vsize 11951MB | residentFast 599MB | heapAllocated 268MB
[task 2022-12-10T00:27:34.267Z] 00:27:34     INFO - TEST-OK | comm/calendar/test/browser/invitations/browser_imipBarRepeatUpdates.js | took 96207ms
[task 2022-12-10T00:27:34.268Z] 00:27:34     INFO - checking window state
[task 2022-12-10T00:27:34.269Z] 00:27:34     INFO - TEST-START | comm/calendar/test/browser/invitations/browser_imipBarUpdates.js
[task 2022-12-10T00:28:00.633Z] 00:28:00     INFO - GECKO(3008) | 1670632080632	addons.xpi	ERROR	System addon update list error Error: got node name: html, expected: updates
[task 2022-12-10T00:29:08.757Z] 00:29:08     INFO - GECKO(3008) | MEMORY STAT | vsize 11952MB | residentFast 626MB | heapAllocated 296MB
[task 2022-12-10T00:29:08.759Z] 00:29:08     INFO - TEST-OK | comm/calendar/test/browser/invitations/browser_imipBarUpdates.js | took 94487ms
[task 2022-12-10T00:29:08.762Z] 00:29:08     INFO - checking window state

```
Sorry I failed to record which test  from which job the above log URL was found.
It starts with the following line, and I presume someone knows how to identify it.
```
[taskcluster 2022-12-10 00:14:14.536Z] Task ID: S8NYBBWRSHOV-HcqVVQfLg
[taskcluster 2022-12-10 00:14:14.536Z] Worker ID: 5721714366428903002
[taskcluster 2022-12-10 00:14:14.536Z] Worker Group: us-west1

```

I doubt if the issue is related to the particular test recorded above because 
my local log with FULL DEBUG version of C-C TB recorded the following during the execution of different test, comm/calendar/test/browser/eventDialog/browser_attendeesDialog.js:
```
05:32.03 INFO Console message: [JavaScript Error: "Invalid ETag value "undefined"" {file: "resource://services-settings/SyncHistory.jsm" line: 52}]
store@resource://services-settings/SyncHistory.jsm:52:13
editAttendees@chrome://calendar/content/calendar-item-iframe.js:1987:13
receiveMessage@chrome://calendar/content/calendar-item-iframe.js:252:7
```

I am posting this because I feel this could be a reason for the test, comm/calendar/test/browser/eventDialog/browser_attendeesDialog.js,  to time out due to the disturbance from this bug. (I will file this timeout issue separately, but has a nagging feeling that they are related. It seems only to occur in FULL DEBUG version of C-C TB, and this is problematic for checking the sanity of my locally created patches before posting them to bugzilla for possible inclusion since I have extended the time out to a very large value (1 hour) to accommodate the slowdown of valgrind and the timeout of comm/calendar/test/browser/eventDialog/browser_attendeesDialog.js hits this maximum constantly.) More on the timeout in the saparately filed bug.