RenderingObject logging utils emit parts of info to stderr, as we see https://github.com/WebKit/WebKit/blob/main/Source/WebCore/rendering/RenderObject.cpp#L2736-L2761 . This doesn't work well on Windows, and platform independent logging should have used WTFLogAlways instead.
Here is permalink to the corresponding sources https://github.com/WebKit/WebKit/blob/8d2e51d04796823702b47e48943d3dd735d67eae/Source/WebCore/rendering/RenderObject.cpp#L2736-L2761 .
Pull request: https://github.com/WebKit/WebKit/pull/28224
Committed 278532@main (63eb3f6b9a35): <https://commits.webkit.org/278532@main> Reviewed commits have been landed. Closing PR #28224 and removing active labels.
<rdar://problem/127768950>