It should be possible to installsrc sources for tools like WebKitTestRunner, as an opt-in. Maybe it's ok to do unconditionally, but I'll start with a small change.
<rdar://problem/101182524>
Pull request: https://github.com/WebKit/WebKit/pull/5388
Committed 255609@main (bb8c8f04c51d): <https://commits.webkit.org/255609@main> Reviewed commits have been landed. Closing PR #5388 and removing active labels.