This is noticeable specially when running only the WPT test harness, the first test(s) would sometimes fail because they were performed before the HTTP server finished its startup procedure.
Pull request: https://github.com/WebKit/WebKit/pull/6683
Committed 256945@main (a4f3bf81be81): <https://commits.webkit.org/256945@main> Reviewed commits have been landed. Closing PR #6683 and removing active labels.
<rdar://problem/102610528>