2027953 - Intermittent devtools/client/debugger/test/mochitest/sourcemaps/browser_dbg-sourcemaps-reloading.js | single tracking bug

Status: RESOLVED FIXED

(DevTools :: Debugger, defect, P5)

Description

[Treeherder Bug Filer]

Filed by: rperta [at] mozilla.com
Parsed log: https://treeherder.mozilla.org/logviewer?job_id=556841268&repo=mozilla-beta&task=aMoQemMTQte32ccg02kL5Q.0
Full log: https://firefox-ci-tc.services.mozilla.com/api/queue/v1/task/aMoQemMTQte32ccg02kL5Q/runs/0/artifacts/public/logs/live_backing.log

---

[task 2026-03-31T01:07:03.540+00:00] 01:07:03     INFO - TEST-PASS | devtools/client/debugger/test/mochitest/sourcemaps/browser_dbg-sourcemaps-reloading.js | Regular breakpoint doesn't have log on line 15
[task 2026-03-31T01:07:03.540+00:00] 01:07:03     INFO - Resuming from 5
[task 2026-03-31T01:07:03.541+00:00] 01:07:03     INFO - Waiting for the debugger to resume
[task 2026-03-31T01:07:03.542+00:00] 01:07:03     INFO - Waiting for state change: 
[task 2026-03-31T01:07:03.542+00:00] 01:07:03     INFO - Finished waiting for state change: 
[task 2026-03-31T01:07:03.543+00:00] 01:07:03     INFO - Wait for reload to complete after resume
[task 2026-03-31T01:07:03.544+00:00] 01:07:03     INFO - \u2192 page loaded
[task 2026-03-31T01:07:03.545+00:00] 01:07:03     INFO - Wait for the toolbox to reload
[task 2026-03-31T01:07:03.549+00:00] 01:07:03     INFO - Waiting for toolbox commands to be reloaded
[task 2026-03-31T01:07:03.549+00:00] 01:07:03     INFO - Waiting for target switch
[task 2026-03-31T01:07:03.553+00:00] 01:07:03     INFO - \u2192 switched-target emitted
[task 2026-03-31T01:07:03.556+00:00] 01:07:03     INFO - Waiting for 'dom-complete' resource
[task 2026-03-31T01:07:03.556+00:00] 01:07:03     INFO - \u2192 'dom-complete' resource emitted
[task 2026-03-31T01:07:03.558+00:00] 01:07:03     INFO - Waiting for jsdebugger to be reloaded
[task 2026-03-31T01:07:03.558+00:00] 01:07:03     INFO - Waiting for jsdebugger updates after page reload
[task 2026-03-31T01:07:03.559+00:00] 01:07:03     INFO - Received 'reloaded' event for jsdebugger
[task 2026-03-31T01:07:03.560+00:00] 01:07:03     INFO - \u2192 panel reloaded
[task 2026-03-31T01:07:03.561+00:00] 01:07:03     INFO - Wait for Responsive UI to reload
[task 2026-03-31T01:07:03.561+00:00] 01:07:03     INFO - Waiting on sources: opts.js
[task 2026-03-31T01:07:03.562+00:00] 01:07:03     INFO - Finished waiting on sources: opts.js
[task 2026-03-31T01:07:03.562+00:00] 01:07:03     INFO - Buffered messages finished
[task 2026-03-31T01:07:03.565+00:00] 01:07:03     INFO - TEST-UNEXPECTED-FAIL | devtools/client/debugger/test/mochitest/sourcemaps/browser_dbg-sourcemaps-reloading.js | A promise chain failed to handle a rejection: sourceContents failed: TypeError: can't access property "threadFront", target is undefined - stack: loadGeneratedSource@resource://devtools/client/debugger/src/actions/sources/loadSourceText.js:37:11
[task 2026-03-31T01:07:03.565+00:00] 01:07:03     INFO - async*loadGeneratedSourceTextPromise@resource://devtools/client/debugger/src/actions/sources/loadSourceText.js:89:16
[task 2026-03-31T01:07:03.565+00:00] 01:07:03     INFO - action@resource://devtools/client/debugger/src/actions/sources/loadSourceText.js:191:69
[task 2026-03-31T01:07:03.566+00:00] 01:07:03     INFO - memoizeableAction/</</<@resource://devtools/client/debugger/src/utils/memoizableAction.js:54:19
[task 2026-03-31T01:07:03.566+00:00] 01:07:03     INFO - memoizeableAction/</<@resource://devtools/client/debugger/src/utils/memoizableAction.js:60:11
[task 2026-03-31T01:07:03.566+00:00] 01:07:03     INFO - thunk/</</<@resource://devtools/client/shared/redux/middleware/thunk.js:17:11
[task 2026-03-31T01:07:03.566+00:00] 01:07:03     INFO - dispatch@resource://devtools/client/shared/vendor/redux.js:681:28
[task 2026-03-31T01:07:03.566+00:00] 01:07:03     INFO - loadSourceText/<@resource://devtools/client/debugger/src/actions/sources/loadSourceText.js:247:12
[task 2026-03-31T01:07:03.566+00:00] 01:07:03     INFO - thunk/</</<@resource://devtools/client/shared/redux/middleware/thunk.js:17:11
[task 2026-03-31T01:07:03.566+00:00] 01:07:03     INFO - dispatch@resource://devtools/client/shared/vendor/redux.js:681:28
[task 2026-03-31T01:07:03.566+00:00] 01:07:03     INFO - checkPendingBreakpoints/<@resource://devtools/client/debugger/src/actions/sources/newSources.js:197:11
[task 2026-03-31T01:07:03.567+00:00] 01:07:03     INFO - thunk/</</<@resource://devtools/client/shared/redux/middleware/thunk.js:17:11
[task 2026-03-31T01:07:03.567+00:00] 01:07:03     INFO - dispatch@resource://devtools/client/shared/vendor/redux.js:681:28
[task 2026-03-31T01:07:03.567+00:00] 01:07:03     INFO - newGeneratedSources/</<@resource://devtools/client/debugger/src/actions/sources/newSources.js:367:17
[task 2026-03-31T01:07:03.567+00:00] 01:07:03     INFO - async*newGeneratedSources/<@resource://devtools/client/debugger/src/actions/sources/newSources.js:369:7
[task 2026-03-31T01:07:03.567+00:00] 01:07:03     INFO - async*thunk/</</<@resource://devtools/client/shared/redux/middleware/thunk.js:17:11
[task 2026-03-31T01:07:03.567+00:00] 01:07:03     INFO - dispatch@resource://devtools/client/shared/redux/visibilityHandlerStore.js:59:20
[task 2026-03-31T01:07:03.567+00:00] 01:07:03     INFO - bindActionCreator/<@resource://devtools/client/shared/vendor/redux.js:520:12
[task 2026-03-31T01:07:03.567+00:00] 01:07:03     INFO - onSourceAvailable@resource://devtools/client/debugger/src/client/firefox.js:233:17
[task 2026-03-31T01:07:03.567+00:00] 01:07:03     INFO - _forwardExistingResources@resource://devtools/shared/commands/resource/resource-command.js:1146:13
[task 2026-03-31T01:07:03.567+00:00] 01:07:03     INFO - watchResources@resource://devtools/shared/commands/resource/resource-command.js:279:18
[task 2026-03-31T01:07:03.567+00:00] 01:07:03     INFO - async*onConnect@resource://devtools/client/debugger/src/client/firefox.js:96:25
[task 2026-03-31T01:07:03.567+00:00] 01:07:03     INFO - async*bootstrap@resource://devtools/client/debugger/src/main.js:142:29
[task 2026-03-31T01:07:03.567+00:00] 01:07:03     INFO - async*open@resource://devtools/client/debugger/panel.js:101:36
[task 2026-03-31T01:07:03.567+00:00] 01:07:03     INFO - async*onLoad@resource://devtools/client/framework/toolbox.js:2866:27
[task 2026-03-31T01:07:03.567+00:00] 01:07:03     INFO - Rejection date: Tue Mar 31 2026 01:07:01 GMT+0000 (Coordinated Universal Time) - false == true
[task 2026-03-31T01:07:03.567+00:00] 01:07:03     INFO - resource://testing-common/PromiseTestUtils.sys.mjs:assertNoUncaughtRejections:266
[task 2026-03-31T01:07:03.567+00:00] 01:07:03     INFO - chrome://mochikit/content/browser-test.js:handleTask:1408
[task 2026-03-31T01:07:03.567+00:00] 01:07:03     INFO - chrome://mochikit/content/browser-test.js:_runTaskBasedTest:1466
[task 2026-03-31T01:07:03.567+00:00] 01:07:03     INFO - chrome://mochikit/content/browser-test.js:Tester_execTest:1617
[task 2026-03-31T01:07:03.567+00:00] 01:07:03     INFO - chrome://mochikit/content/browser-test.js:nextTest/<:1356
[task 2026-03-31T01:07:03.567+00:00] 01:07:03     INFO - chrome://mochikit/content/tests/SimpleTest/SimpleTest.js:SimpleTest.waitForFocus/<:1060
[task 2026-03-31T01:07:03.569+00:00] 01:07:03     INFO - Leaving test 
[task 2026-03-31T01:07:03.569+00:00] 01:07:03     INFO - Removing tab.
[task 2026-03-31T01:07:03.570+00:00] 01:07:03     INFO - Waiting for event: 'TabClose' on [object XULElement].
[task 2026-03-31T01:07:03.571+00:00] 01:07:03     INFO - Got event: 'TabClose' on [object XULElement].
[task 2026-03-31T01:07:03.571+00:00] 01:07:03     INFO - Tab removed and finished closing
[task 2026-03-31T01:07:03.571+00:00] 01:07:03     INFO - GECKO(1192) | JavaScript error: , line 0: NotFoundError: No such JSProcessActor 'DevToolsProcess'
[task 2026-03-31T01:07:03.572+00:00] 01:07:03     INFO - GECKO(1192) | JavaScript error: , line 0: NotFoundError: No such JSProcessActor 'DevToolsProcess'
[task 2026-03-31T01:07:03.572+00:00] 01:07:03     INFO - GECKO(1192) | JavaScript error: , line 0: NotFoundError: No such JSProcessActor 'DevToolsProcess'
[task 2026-03-31T01:07:03.573+00:00] 01:07:03     INFO - Console message: [JavaScript Error: "NotFoundError: No such JSProcessActor 'DevToolsProcess'"]
[task 2026-03-31T01:07:03.574+00:00] 01:07:03     INFO - Console message: [JavaScript Error: "NotFoundError: No such JSProcessActor 'DevToolsProcess'"]
[task 2026-03-31T01:07:03.575+00:00] 01:07:03     INFO - Console message: [JavaScript Error: "NotFoundError: No such JSProcessActor 'DevToolsProcess'"]
[task 2026-03-31T01:07:03.575+00:00] 01:07:03     INFO - TEST-PASS | devtools/client/debugger/test/mochitest/sourcemaps/browser_dbg-sourcemaps-reloading.js | The main process DevToolsServer has no pending connection when the test ends
[task 2026-03-31T01:07:03.893+00:00] 01:07:03     INFO - GECKO(1192) | MEMORY STAT | vsize 2121198MB | vsizeMaxContiguous 65083052MB | residentFast 749MB | heapAllocated 240MB
[task 2026-03-31T01:07:03.895+00:00] 01:07:03     INFO - checking for open sidebars
[task 2026-03-31T01:07:03.895+00:00] 01:07:03     INFO - checking window state
[task 2026-03-31T01:07:03.896+00:00] 01:07:03     INFO - Not taking screenshot here: see the one that was previously logged
[task 2026-03-31T01:07:03.896+00:00] 01:07:03     INFO - TEST-UNEXPECTED-FAIL | devtools/client/debugger/test/mochitest/sourcemaps/browser_dbg-sourcemaps-reloading.js | finished in 2832ms
[task 2026-03-31T01:07:03.896+00:00] 01:07:03     INFO - TEST-INFO took 2846ms
[task 2026-03-31T01:07:03.909+00:00] 01:07:03     INFO - TEST-START | devtools/client/debugger/test/mochitest/sourcemaps/browser_dbg-sourcemaps.js
[task 2026-03-31T01:07:05.083+00:00] 01:07:05     INFO - GECKO(1192) | JavaScript error: https://example.com/browser/devtools/client/debugger/test/mochitest/examples/sourcemaps-with-sections/xbundle.js, line 5: Error: error
[task 2026-03-31T01:07:06.121+00:00] 01:07:06     INFO - GECKO(1192) | JavaScript error: https://example.com/browser/devtools/client/debugger/test/mochitest/examples/sourcemaps-with-sections/xbundle.js, line 5: Error: error
[task 2026-03-31T01:07:09.002+00:00] 01:07:09     INFO - GECKO(1192) | JavaScript error: https://example.com/browser/devtools/client/debugger/test/mochitest/examples/sourcemaps-with-sections/xbundle.js, line 5: Error: error
[task 2026-03-31T01:07:09.432+00:00] 01:07:09     INFO - GECKO(1192) | JavaScript error: , line 0: NotFoundError: No such JSProcessActor 'DevToolsProcess'
[task 2026-03-31T01:07:09.432+00:00] 01:07:09     INFO - GECKO(1192) | JavaScript error: , line 0: NotFoundError: No such JSProcessActor 'DevToolsProcess'
[task 2026-03-31T01:07:09.432+00:00] 01:07:09     INFO - GECKO(1192) | JavaScript error: , line 0: NotFoundError: No such JSProcessActor 'DevToolsProcess'
[task 2026-03-31T01:07:09.432+00:00] 01:07:09     INFO - GECKO(1192) | JavaScript error: , line 0: NotFoundError: No such JSProcessActor 'DevToolsProcess'
[task 2026-03-31T01:07:09.434+00:00] 01:07:09     INFO - GECKO(1192) | JavaScript error: , line 0: NotFoundError: No such JSProcessActor 'DevToolsProcess'
[task 2026-03-31T01:07:09.777+00:00] 01:07:09     INFO - GECKO(1192) | MEMORY STAT | vsize 2121159MB | vsizeMaxContiguous 65083052MB | residentFast 656MB | heapAllocated 151MB
[task 2026-03-31T01:07:09.783+00:00] 01:07:09     INFO - TEST-PASS | devtools/client/debugger/test/mochitest/sourcemaps/browser_dbg-sourcemaps.js | took 5873ms
[task 2026-03-31T01:07:09.796+00:00] 01:07:09     INFO - TEST-START | devtools/client/debugger/test/mochitest/sourcemaps/browser_dbg-sourcemaps2.js
[task 2026-03-31T01:07:12.145+00:00] 01:07:12     INFO - GECKO(1192) | JavaScript error: , line 0: NotFoundError: No such JSProcessActor 'DevToolsProcess'
[task 2026-03-31T01:07:12.157+00:00] 01:07:12     INFO - GECKO(1192) | JavaScript error: , line 0: NotFoundError: No such JSProcessActor 'DevToolsProcess'
[task 2026-03-31T01:07:12.157+00:00] 01:07:12     INFO - GECKO(1192) | JavaScript error: , line 0: NotFoundError: No such JSProcessActor 'DevToolsProcess'
[task 2026-03-31T01:07:12.157+00:00] 01:07:12     INFO - GECKO(1192) | JavaScript error: , line 0: NotFoundError: No such JSProcessActor 'DevToolsProcess'
[task 2026-03-31T01:07:12.158+00:00] 01:07:12     INFO - GECKO(1192) | JavaScript error: , line 0: NotFoundError: No such JSProcessActor 'DevToolsProcess'
[task 2026-03-31T01:07:12.493+00:00] 01:07:12     INFO - GECKO(1192) | MEMORY STAT | vsize 2121169MB | vsizeMaxContiguous 65083052MB | residentFast 658MB | heapAllocated 162MB
[task 2026-03-31T01:07:12.501+00:00] 01:07:12     INFO - TEST-PASS | devtools/client/debugger/test/mochitest/sourcemaps/browser_dbg-sourcemaps2.js | took 2702ms

Comment 1

[Intermittent Failures Robot]

4 failures were associated with this bug in the last 7 days.

Repository breakdown:

• mozilla-beta: 4

Table

	no_variant
windows11-x86_64/opt	4

For more details, see:

https://treeherder.mozilla.org/intermittent-failures/bugdetails?bug=2027953&startday=2026-03-30&endday=2026-04-05&tree=all

Comment 2

[Intermittent Failures Robot]

1 failures were associated with this bug in the last 7 days.

Repository breakdown:

• mozilla-beta: 1

Table

	no_variant
windows11-x86_64/opt	1

For more details, see:

https://treeherder.mozilla.org/intermittent-failures/bugdetails?bug=2027953&startday=2026-04-08&endday=2026-04-14&tree=all

Comment 3

[Intermittent Failures Robot]

1 failures were associated with this bug in the last 7 days.

Repository breakdown:

• mozilla-release: 1

Table

	no_variant
windows11-x86_64/opt	1

For more details, see:

https://treeherder.mozilla.org/intermittent-failures/bugdetails?bug=2027953&startday=2026-04-20&endday=2026-04-26&tree=all

Comment 4

[Intermittent Failures Robot]

3 failures were associated with this bug in the last 7 days.

Repository breakdown:

• mozilla-beta: 2
• mozilla-release: 1

Table

	no_variant
macosx1500-aarch64/opt	3

For more details, see:

https://treeherder.mozilla.org/intermittent-failures/bugdetails?bug=2027953&startday=2026-04-27&endday=2026-05-03&tree=all

Comment 5

[Intermittent Failures Robot]

2 failures were associated with this bug in the last 7 days.

Repository breakdown:

• mozilla-beta: 2

Table

	no_variant
windows11-x86_64/opt	2

For more details, see:

https://treeherder.mozilla.org/intermittent-failures/bugdetails?bug=2027953&startday=2026-05-04&endday=2026-05-10&tree=all

Comment 6

[Intermittent Failures Robot]

1 failures were associated with this bug in the last 7 days.

Repository breakdown:

• mozilla-beta: 1

Table

	no_variant
macosx1500-aarch64/opt	1

For more details, see:

https://treeherder.mozilla.org/intermittent-failures/bugdetails?bug=2027953&startday=2026-05-11&endday=2026-05-17&tree=all

Comment 7

[Intermittent Failures Robot]

1 failures were associated with this bug in the last 7 days.

Repository breakdown:

• mozilla-release: 1

Table

	no_variant
windows11-x86_64/opt	1

For more details, see:

https://treeherder.mozilla.org/intermittent-failures/bugdetails?bug=2027953&startday=2026-05-18&endday=2026-05-24&tree=all

Comment 8

[Intermittent Failures Robot]

1 failures were associated with this bug in the last 7 days.

Repository breakdown:

• mozilla-release: 1

Table

	no_variant
windows11-x86_64/opt	1

For more details, see:

https://treeherder.mozilla.org/intermittent-failures/bugdetails?bug=2027953&startday=2026-06-01&endday=2026-06-07&tree=all

Comment 9

[BugBot [:suhaib / :marco]]

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

Comment 10

[Florian Quèze [:florian]]

Attachment: Bug 2027953 - [devtools] Don't sync breakpoints against a destroyed target, r=#devtools-reviewers.

newGeneratedSources checks that a source actor's target is alive when the
resource comes in, but not after awaiting the source maps, and then dispatches
checkPendingBreakpoints without awaiting it. A target destroyed in that window
leaves an unhandled targetFront.getSourceContentForResource failed: TypeError: this.commands is undefined rejection, which fails
sourcemaps/browser_dbg-sourcemaps-reloading.js and browser_dbg-reloading.js.

Comment 11

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/535a0dee531d
https://hg.mozilla.org/integration/autoland/rev/ae1cc277945b
[devtools] Don't sync breakpoints against a destroyed target, r=devtools-reviewers,ochameau.

Comment 12

[Silaghi Andreea]

https://hg.mozilla.org/mozilla-central/rev/ae1cc277945b