301587 2025-10-28 12:30:25 -0700 REGRESSION(302222@main) [ Tahoe ]: 14 TestWebKitAPI.CSSViewportUnits (api-tests) are constant failures 2025-10-28 19:14:25 -0700 1 1 1 Unclassified WebKit Scrolling WebKit Nightly Build Unspecified Unspecified RESOLVED FIXED https://bugs.webkit.org/show_bug.cgi?id=299577 InRadar P2 Normal --- 299577 1 jenner simon.fraser simon.fraser webkit-bot-watchers-bugzilla webkit-bug-importer oldest_to_newest 2154793 0 jenner 2025-10-28 12:30:25 -0700 The following 14 API-tests are constant failures, observed on Tahoe: TestWebKitAPI.CSSViewportUnits.AllSame TestWebKitAPI.CSSViewportUnits.MaximumViewportInset TestWebKitAPI.CSSViewportUnits.MaximumViewportInsetWithBounds TestWebKitAPI.CSSViewportUnits.MaximumViewportInsetWithFrame TestWebKitAPI.CSSViewportUnits.MaximumViewportInsetWithWritingMode TestWebKitAPI.CSSViewportUnits.MaximumViewportInsetWithZoom TestWebKitAPI.CSSViewportUnits.MinimumViewportInset TestWebKitAPI.CSSViewportUnits.MinimumViewportInsetWithBounds TestWebKitAPI.CSSViewportUnits.MinimumViewportInsetWithFrame TestWebKitAPI.CSSViewportUnits.MinimumViewportInsetWithTopContentInset TestWebKitAPI.CSSViewportUnits.MinimumViewportInsetWithWritingMode TestWebKitAPI.CSSViewportUnits.MinimumViewportInsetWithZoom TestWebKitAPI.CSSViewportUnits.SVGDocument TestWebKitAPI.WKScrollGeometry.ContentSizeTallerThanWebView HISTORY: https://results.webkit.org/?suite=api-tests&suite=api-tests&suite=api-tests&suite=api-tests&suite=api-tests&suite=api-tests&suite=api-tests&suite=api-tests&suite=api-tests&suite=api-tests&suite=api-tests&suite=api-tests&suite=api-tests&suite=api-tests&test=TestWebKitAPI.CSSViewportUnits.AllSame&test=TestWebKitAPI.CSSViewportUnits.MaximumViewportInset&test=TestWebKitAPI.CSSViewportUnits.MaximumViewportInsetWithBounds&test=TestWebKitAPI.CSSViewportUnits.MaximumViewportInsetWithFrame&test=TestWebKitAPI.CSSViewportUnits.MaximumViewportInsetWithWritingMode&test=TestWebKitAPI.CSSViewportUnits.MaximumViewportInsetWithZoom&test=TestWebKitAPI.CSSViewportUnits.MinimumViewportInset&test=TestWebKitAPI.CSSViewportUnits.MinimumViewportInsetWithBounds&test=TestWebKitAPI.CSSViewportUnits.MinimumViewportInsetWithFrame&test=TestWebKitAPI.CSSViewportUnits.MinimumViewportInsetWithTopContentInset&test=TestWebKitAPI.CSSViewportUnits.MinimumViewportInsetWithWritingMode&test=TestWebKitAPI.CSSViewportUnits.MinimumViewportInsetWithZoom&test=TestWebKitAPI.CSSViewportUnits.SVGDocument&test=TestWebKitAPI.WKScrollGeometry.ContentSizeTallerThanWebView 2154794 1 webkit-bug-importer 2025-10-28 12:31:22 -0700 <rdar://problem/163584974> 2154795 2 jenner 2025-10-28 12:33:29 -0700 All 14 of the tests appear to have a similar failure. Here is an example of one of them: "name": "TestWebKitAPI.CSSViewportUnits.MaximumViewportInset", "output": "2025-10-28 00:06:13.613 TestWebKitAPI[9761:353541] NSEventConcurrentProcessingEnabled=NO\n\n/Volumes/Data/worker/Apple-Tahoe-Debug-Build/build/Tools/TestWebKitAPI/Tests/WebKitCocoa/CSSViewportUnits.mm:375\nExpected equality of these values:\n fixedWidth\n Which is: 317\n viewportUnitLength(webView, @\"dvw\")\n Which is: 320\n\n\n\n/Volumes/Data/worker/Apple-Tahoe-Debug-Build/build/Tools/TestWebKitAPI/Tests/WebKitCocoa/CSSViewportUnits.mm:377\nExpected equality of these values:\n fixedWidth\n Which is: 317\n viewportUnitLength(webView, @\"dvmin\")\n Which is: 320\n\n\n\n/Volumes/Data/worker/Apple-Tahoe-Debug-Build/build/Tools/TestWebKitAPI/Tests/WebKitCocoa/CSSViewportUnits.mm:380\nExpected equality of these values:\n fixedWidth\n Which is: 317\n viewportUnitLength(webView, @\"dvi\")\n Which is: 320" }, Every failure can be observed at the following link: https://build.webkit.org/api/v2/logs/45420252/raw_inline 2154798 3 jenner 2025-10-28 12:34:55 -0700 I have also reproduced all of these failures at macOS Tahoe Debug ToT running as follows: run-api-tests <test_goes_here> I have also confirmed that these tests all fail starting at 302222@main, but pass at 302221@main So it appears that: https://commits.webkit.org/302222@main is our regression point. 2154883 4 ews-feeder 2025-10-28 19:14:22 -0700 Committed 302273@main (9d69381d1353): <https://commits.webkit.org/302273@main> Reviewed commits have been landed. Closing PR #53119 and removing active labels.