It seems that we were depending on some implicit setting before and that no longer exists on my system on in the global CMake build. See 126582.
Created attachment 220679 [details] Patch for landing
Comment on attachment 220679 [details] Patch for landing Clearing flags on attachment: 220679 Committed r161528: <http://trac.webkit.org/changeset/161528>
All reviewed patches have been landed. Closing bug.