The instructions for getting the code using subversion at https://webkit.org/getting-the-code/#checking-out-with-subversion don't currently account for gatekeeper, so when building for the first time, you get informed of issues with certain scripts like `Source/JavaScriptCore/postprocess-headers.sh`. The work around is to run xattr -c Source/JavaScriptCore/postprocess-headers.sh, but given this, we should consider just removing the tarballs and encouraging people to checkout using svn checkout and/or to use git.
Another issue with tarballs is that timestamps are not fully preserved, making all svn operations extremely slow.
<rdar://problem/78066912>