Bug 264527 – REGRESSION (270319@main): [Ventura+ iOS17 ]imported/w3c/web-platform-tests/css/css-cascade/idlharness.html is a flaky failure

• Status: NEW
• Component: New Bugs

[Marta Darbinyan]

Description:
imported/w3c/web-platform-tests/css/css-cascade/idlharness.html is a flaky on macOS Monterey, Sonoma and iOS17 ToT since 270319@main introduced.

This issue can be reproduced by using the command: 
run-webkit-tests --release --iterations=50 imported/w3c/web-platform-tests/css/css-cascade/idlharness.html

History:
https://results.webkit.org/?suite=layout-tests&test=imported%2Fw3c%2Fweb-platform-tests%2Fcss%2Fcss-cascade%2Fidlharness.html&architecture=arm64

Diff Log:
FAIL idl_test setup promise_test: Unhandled rejection with value: object "Error fetching /interfaces/css-cascade.idl."
FAIL idl_test setup promise_test: Unhandled rejection with value: object "Error fetching /interfaces/css-cascade-6.idl."

Link:
https://build.webkit.org/results/Apple-Sonoma-Release-AppleSilicon-WK2-Tests/270445@main%20(724)/imported/w3c/web-platform-tests/css/css-cascade/idlharness-pretty-diff.html

[Radar WebKit Bug Importer]

<rdar://problem/118203546>

[EWS]

Test gardening commit 270485@main (cd98c8bfca4c): <https://commits.webkit.org/270485@main>

Reviewed commits have been landed. Closing PR #20267 and removing active labels.