script: Log uncaught JS exceptions to the console by simonwuelker · Pull Request #43191 · servo/servo

simonwuelker · 2026-03-11T19:52:49Z

The script execution code has changed a bit in the last months so some things that used to work don't anymore.

This change ensures that when an exception is thrown it is logged to the console.

Testing: Regressions are covered by wpt, but we can't run tests for the presence of log::error! calls

Signed-off-by: Simon Wülker <simon.wuelker@arcor.de>

github-actions · 2026-03-11T20:00:18Z

🔨 Triggering try run (#22971848928) for Linux (WPT)

github-actions · 2026-03-11T21:18:34Z

Test results for linux-wpt from try job (#22971848928):

Flaky unexpected result (28)

PASS [expected FAIL] /_mozilla/css/linear_gradients_reverse_a.html
ERROR [expected OK] /_mozilla/mozilla/preserve_wrapper_callback.html
CRASH [expected PASS] /_mozilla/shadow-dom/move-element-with-ua-shadow-tree-crash.html (#39473)
CRASH [expected OK] /_webgl/conformance/canvas/drawingbuffer-static-canvas-test.html
FAIL [expected PASS] /css/css-backgrounds/background-size-041.html
OK /css/css-fonts/generic-family-keywords-002.html (#40929)
- FAIL [expected PASS] subtest: font-family: -webkit-serif treated as <font-family>, not <generic-name>
```
assert_equals: expected 30 but got 50
```
- FAIL [expected PASS] subtest: font-family: -webkit-sans-serif treated as <font-family>, not <generic-name>
```
assert_equals: expected 30 but got 50
```
- FAIL [expected PASS] subtest: font-family: -webkit-cursive treated as <font-family>, not <generic-name>
```
assert_equals: expected 30 but got 50
```
- FAIL [expected PASS] subtest: font-family: -webkit-fantasy treated as <font-family>, not <generic-name>
```
assert_equals: expected 30 but got 50
```
- FAIL [expected PASS] subtest: font-family: -webkit-monospace treated as <font-family>, not <generic-name>
```
assert_equals: expected 30 but got 50
```
- FAIL [expected PASS] subtest: font-family: -webkit-system-ui treated as <font-family>, not <generic-name>
```
assert_equals: expected 30 but got 50
```
- FAIL [expected PASS] subtest: font-family: -webkit-math treated as <font-family>, not <generic-name>
```
assert_equals: expected 30 but got 50
```
- PASS [expected FAIL] subtest: font-family: -webkit-generic(fangsong) treated as <font-family>, not <generic-name>
- PASS [expected FAIL] subtest: font-family: -webkit-generic(kai) treated as <font-family>, not <generic-name>
- PASS [expected FAIL] subtest: font-family: -webkit-generic(khmer-mul) treated as <font-family>, not <generic-name>
- And 12 more unexpected results...
OK [expected ERROR] /fetch/fetch-later/quota/same-origin-iframe/sandboxed-iframe.https.window.html (#41704)
OK /html/browsers/browsing-the-web/navigating-across-documents/initial-empty-document/load-pageshow-events-window-open.html (#28691)
- FAIL [expected PASS] subtest: load event does not fire on window.open('about:blank')
```
assert_unreached: load should not be fired Reached unreachable code
```
OK /html/browsers/browsing-the-web/navigating-across-documents/navigation-unload-same-origin.window.html (#29049)
- PASS [expected FAIL] subtest: Same-origin navigation started from unload handler must be ignored
OK /html/browsers/history/the-history-interface/traverse_the_history_4.html (#21383)
- FAIL [expected PASS] subtest: Multiple history traversals, last would be aborted
```
assert_array_equals: Pages opened during history navigation expected property 1 to be 5 but got 3 (expected array [6, 5] got [6, 3])
```

OK /html/browsers/windows/embedded-opener-remove-frame.html (#23867)

FAIL [expected PASS] subtest: opener of discarded auxiliary browsing context

assert_object_equals: property "get" expected function "function opener() {
    [native code]
}" got function "function opener() {
    [native code]
}"

CRASH [expected OK] /html/canvas/element/color-type/2d.color.type.u8p3.to.u8srgb.to.u8p3.html
TIMEOUT [expected OK] /html/interaction/focus/the-autofocus-attribute/autofocus-dialog.html (#29087)
- TIMEOUT [expected FAIL] subtest: <dialog>-contained autofocus element gets focused when the dialog is shown
```
Test timed out
```
OK /html/semantics/embedded-content/media-elements/media_fragment_seek.html (#24114)
- FAIL [expected PASS] subtest: Video should seek to time specified in media fragment syntax
```
assert_equals: expected 3 but got 0
```
TIMEOUT /html/semantics/embedded-content/media-elements/preserves-pitch.html (#40352)
- PASS [expected TIMEOUT] subtest: Speed-ups should not change the pitch when preservesPitch=true
- PASS [expected NOTRUN] subtest: Slow-downs should not change the pitch when preservesPitch=true
- TIMEOUT [expected NOTRUN] subtest: Speed-ups should change the pitch when preservesPitch=false
```
Test timed out
```

OK /html/semantics/embedded-content/the-iframe-element/iframe-loading-lazy-nav-window-open.html (#32596)

FAIL [expected PASS] subtest: Navigating iframe loading='lazy' before it is loaded: location.replace

uncaught exception: Error: assert_equals: expected "http://web-platform.test:8000/html/semantics/embedded-content/the-iframe-element/support/blank.htm?nav" but got "http://web-platform.test:8000/html/semantics/embedded-content/the-iframe-element/support/blank.htm?src"

TIMEOUT [expected OK] /html/semantics/embedded-content/the-iframe-element/iframe_sandbox_navigate_other_frame_popup.sub.html (#39702)
- TIMEOUT [expected FAIL] subtest: Sandboxed iframe can not navigate other frame's popup
```
Test timed out
```
OK /html/semantics/forms/form-submission-0/jsurl-form-submit.tentative.html (#36489)
- PASS [expected FAIL] subtest: Verifies that form submissions scheduled inside javascript: urls take precedence over the javascript: url's return value.
TIMEOUT [expected OK] /html/user-activation/navigation-state-reset-sameorigin.html
- TIMEOUT [expected PASS] subtest: Post-navigation state reset.
```
Test timed out
```
OK /mixed-content/tentative/autoupgrades/video-upgrade.https.sub.html (#41135)
- FAIL [expected PASS] subtest: Video of other host autoupgraded
```
assert_equals: Length. Other host expected 1 but got Infinity
```
FAIL [expected PASS] /png/apng/fcTL-dispose-before-region-background.html
PASS [expected FAIL] /png/apng/fcTL-dispose-none.html (#41817)
OK /pointerevents/compat/pointerevent_touch_target_after_pointerdown_target_removed.tentative.html (#42813)
- PASS [expected FAIL] subtest: After a pointerdown listener moves the target to different position, touch events should be fired on the pointerdown target, but pointer events should be fired on the pointerdown target parent
- PASS [expected FAIL] subtest: After a pointerdown listener moves the target to different position, touchmove event should be fired on the pointerdown target parent
ERROR /service-workers/idlharness.https.any.html (#36250)
- PASS [expected TIMEOUT] subtest: ServiceWorkerContainer interface: operation register((TrustedScriptURL or USVString), optional RegistrationOptions)
- PASS [expected TIMEOUT] subtest: NavigationPreloadManager interface: operation enable()
- PASS [expected TIMEOUT] subtest: NavigationPreloadManager interface: operation disable()
- PASS [expected TIMEOUT] subtest: NavigationPreloadManager interface: operation setHeaderValue(ByteString)
- PASS [expected TIMEOUT] subtest: NavigationPreloadManager interface: operation getState()
OK /touch-events/single-tap-when-touchend-listener-use-sync-xhr.html (#41175)
- PASS [expected FAIL] subtest: Click event should be fired when touchend opens synchronous XHR
OK [expected TIMEOUT] /trusted-types/trusted-types-navigation.html?06-10 (#37920)
- PASS [expected TIMEOUT] subtest: Navigate a frame via anchor with javascript:-urls w/ default policy in report-only mode.
- FAIL [expected NOTRUN] subtest: Navigate a window via anchor with javascript:-urls w/ a default policy throwing an exception in enforcing mode.
```
promise_test: Unhandled rejection with value: "Unexpected message received: \"No securitypolicyviolation reported!\""
```
- FAIL [expected NOTRUN] subtest: Navigate a window via anchor with javascript:-urls w/ a default policy throwing an exception in report-only mode.
```
promise_test: Unhandled rejection with value: "Unexpected message received: \"No securitypolicyviolation reported!\""
```
OK [expected TIMEOUT] /trusted-types/trusted-types-navigation.html?26-30 (#38807)
- PASS [expected TIMEOUT] subtest: Navigate a window via form-submission with javascript:-urls in report-only mode.
- PASS [expected NOTRUN] subtest: Navigate a window via form-submission with javascript:-urls w/ default policy in report-only mode.
- PASS [expected NOTRUN] subtest: Navigate a frame via form-submission with javascript:-urls in enforcing mode.
- PASS [expected NOTRUN] subtest: Navigate a frame via form-submission with javascript:-urls w/ default policy in enforcing mode.
OK [expected TIMEOUT] /webstorage/localstorage-about-blank-3P-iframe-opens-3P-window.partitioned.html (#29053)
- PASS [expected TIMEOUT] subtest: StorageKey: test 3P about:blank window opened from a 3P iframe

Stable unexpected results that are known to be intermittent (19)

OK /_mozilla/css/offset_properties_inline.html (#40543)

FAIL [expected PASS] subtest: offsetTop

assert_equals: offsetTop of #inline-1 should be 0. expected 0 but got -1

FAIL [expected PASS] subtest: offsetLeft

assert_equals: offsetLeft of #inline-2 should be 40. expected 40 but got 25

FAIL [expected PASS] /_mozilla/mozilla/sslfail.html (#10760)
TIMEOUT [expected OK] /_mozilla/mozilla/window_resize_event.html (#36741)
- TIMEOUT [expected PASS] subtest: Popup onresize event fires after resizeTo
```
Test timed out
```
OK /_webgl/conformance/textures/misc/texture-upload-size.html (#21770)
- PASS [expected FAIL] subtest: WebGL test #45
- PASS [expected FAIL] subtest: WebGL test #47
- PASS [expected FAIL] subtest: WebGL test #49
- PASS [expected FAIL] subtest: WebGL test #51
OK /css/css-fonts/generic-family-keywords-003.html (#38994)
- PASS [expected FAIL] subtest: @font-face matching for quoted and unquoted cursive (drawing text in a canvas)
- PASS [expected FAIL] subtest: @font-face matching for quoted and unquoted fantasy (drawing text in a canvas)
- PASS [expected FAIL] subtest: @font-face matching for quoted and unquoted monospace (drawing text in a canvas)
- PASS [expected FAIL] subtest: @font-face matching for quoted and unquoted system-ui (drawing text in a canvas)
- PASS [expected FAIL] subtest: @font-face matching for quoted and unquoted generic(fangsong) (drawing text in a canvas)
- PASS [expected FAIL] subtest: @font-face matching for quoted and unquoted generic(kai) (drawing text in a canvas)
- PASS [expected FAIL] subtest: @font-face matching for quoted and unquoted ui-serif (drawing text in a canvas)
OK /fetch/metadata/generated/css-font-face.https.sub.tentative.html (#32732)
- PASS [expected FAIL] subtest: sec-fetch-user
OK /fetch/metadata/generated/css-font-face.sub.tentative.html (#34624)
- PASS [expected FAIL] subtest: sec-fetch-storage-access - Not sent to non-trustworthy same-origin destination
ERROR /fetch/metadata/generated/serviceworker.https.sub.html (#36247)
- PASS [expected FAIL] subtest: sec-fetch-site - Same origin, no options - registration
OK [expected ERROR] /focus/focus-event-after-switching-iframes.sub.html (#40368)
OK [expected TIMEOUT] /html/anonymous-iframe/indexeddb.tentative.https.window.html (#39254)
- FAIL [expected TIMEOUT] subtest: indexeddb
```
assert_equals: expected (undefined) undefined but got (string) "2bbefa75-ca28-4451-bc70-f06810f4633e"
```
OK /html/browsers/browsing-the-web/navigating-across-documents/navigation-unload-same-origin-fragment.html (#20768)
- FAIL [expected PASS] subtest: Tests that a fragment navigation in the unload handler will not block the initial navigation
```
assert_equals: expected "" but got "#fragment"
```
OK /html/browsers/history/the-history-interface/traverse_the_history_2.html (#21383)
- FAIL [expected PASS] subtest: Multiple history traversals, last would be aborted
```
assert_array_equals: Pages opened during history navigation expected property 1 to be 3 but got 1 (expected array [6, 3] got [6, 1])
```
CRASH [expected TIMEOUT] /html/browsers/history/the-location-interface/location_replace_session_history.html (#41896)
TIMEOUT /html/interaction/focus/the-autofocus-attribute/supported-elements.html (#24145)
- TIMEOUT [expected FAIL] subtest: Element with tabindex should support autofocus
```
Test timed out
```
- NOTRUN [expected PASS] subtest: Non-HTMLElement should not support autofocus
- NOTRUN [expected TIMEOUT] subtest: Host element with delegatesFocus should support autofocus
OK /navigation-timing/test-navigation-type-reload.html (#33334)
- FAIL [expected PASS] subtest: Reload domComplete > Original domComplete
```
assert_true: Reload domComplete &gt; Original domComplete expected true got false
```
- FAIL [expected PASS] subtest: Reload domInteractive > Original domInteractive
```
assert_true: Reload domInteractive &gt; Original domInteractive expected true got false
```
- FAIL [expected PASS] subtest: Reload fetchStart > Original fetchStart
```
assert_true: Reload fetchStart &gt; Original fetchStart expected true got false
```
- FAIL [expected PASS] subtest: Reload loadEventEnd > Original loadEventEnd
```
assert_true: Reload loadEventEnd &gt; Original loadEventEnd expected true got false
```
- FAIL [expected PASS] subtest: Reload loadEventStart > Original loadEventStart
```
assert_true: Reload loadEventStart &gt; Original loadEventStart expected true got false
```
OK /resource-timing/buffer-full-add-then-clear.html (#40819)
- FAIL [expected PASS] subtest: Test that if the buffer is cleared after entries were added to the secondary buffer, those entries make it into the primary one
```
assert_equals: Number of entries does not match the expected value. expected 3 but got 0
```
OK /resource-timing/test_resource_timing.html (#25720)
- PASS [expected FAIL] subtest: PerformanceEntry has correct name, initiatorType, startTime, and duration (iframe)
- FAIL [expected PASS] subtest: PerformanceEntry has correct name, initiatorType, startTime, and duration (link)
```
assert_equals: expected 13.84 but got 13.83
```
OK [expected TIMEOUT] /trusted-types/trusted-types-navigation.html?31-35 (#38034)
- PASS [expected TIMEOUT] subtest: Navigate a frame via form-submission with javascript:-urls w/ default policy in report-only mode.
- FAIL [expected NOTRUN] subtest: Navigate a window via form-submission with javascript:-urls w/ a default policy throwing an exception in enforcing mode.
```
promise_test: Unhandled rejection with value: "Unexpected message received: \"No securitypolicyviolation reported!\""
```
- FAIL [expected NOTRUN] subtest: Navigate a window via form-submission with javascript:-urls w/ a default policy throwing an exception in report-only mode.
```
promise_test: Unhandled rejection with value: "Unexpected message received: \"No securitypolicyviolation reported!\""
```
- FAIL [expected NOTRUN] subtest: Navigate a window via form-submission with javascript:-urls w/ a default policy making the URL invalid in enforcing mode.
```
promise_test: Unhandled rejection with value: "Unexpected message received: \"No securitypolicyviolation reported!\""
```

OK /webaudio/the-audio-api/the-audiobuffersourcenode-interface/sub-sample-buffer-stitching.html (#22849)

FAIL [expected PASS] subtest: buffer-stitching-1

assert_approx_equals: Stitched sine‑wave buffers at sample rate 44100 sample[16770] |0.00004397996235638857 - 0.9055536389350891| = 0.9055096589727327 &gt; 0.000090957 expected 0.9055536389350891 +/- 0.000090957 but got 0.00004397996235638857

Stable unexpected results (1)

OK /webdriver/tests/classic/accept_alert/accept.py
- FAIL [expected PASS] subtest: test_accept_in_popup_window
```
AssertionError: no such alert (404): No user prompt is currently active.
```

github-actions · 2026-03-11T21:18:44Z

⚠️ Try run (#22971848928) failed!

The script execution code has changed a bit in the last months so some things that used to work don't anymore. This change ensures that when an exception is thrown it is logged to the console. Testing: Regressions are covered by wpt, but we can't run tests for the presence of `log::error!` calls --------- Signed-off-by: Simon Wülker <simon.wuelker@arcor.de> (cherry picked from commit 333e195)

script: Log error when reporting an exception

dbff35c

Signed-off-by: Simon Wülker <simon.wuelker@arcor.de>

simonwuelker requested a review from gterzian as a code owner March 11, 2026 19:52

servo-highfive added the S-awaiting-review There is new code that needs to be reviewed. label Mar 11, 2026

simonwuelker changed the title ~~Report errors~~ script: Log uncaught JS exceptions to the console Mar 11, 2026

simonwuelker force-pushed the report-errors branch from 9d00306 to a3e612e Compare March 11, 2026 19:56

script: Fix js-backtrace feature

abcb7ae

Signed-off-by: Simon Wülker <simon.wuelker@arcor.de>

simonwuelker force-pushed the report-errors branch from a3e612e to abcb7ae Compare March 11, 2026 19:59

simonwuelker added the T-linux-wpt Do a try run of the WPT label Mar 11, 2026

github-actions Bot removed the T-linux-wpt Do a try run of the WPT label Mar 11, 2026

TimvdLippe approved these changes Mar 11, 2026

View reviewed changes

servo-highfive removed the S-awaiting-review There is new code that needs to be reviewed. label Mar 11, 2026

simonwuelker added this pull request to the merge queue Mar 11, 2026

servo-highfive added the S-awaiting-merge The PR is in the process of compiling and running tests on the automated CI. label Mar 11, 2026

Merged via the queue into servo:main with commit 333e195 Mar 11, 2026
66 of 68 checks passed

simonwuelker deleted the report-errors branch March 11, 2026 22:41

servo-highfive removed the S-awaiting-merge The PR is in the process of compiling and running tests on the automated CI. label Mar 11, 2026

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script: Log uncaught JS exceptions to the console#43191

script: Log uncaught JS exceptions to the console#43191
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