After <http://trac.webkit.org/r184215> (the fix for bug 144922), the staged XPC services are loading the shims from the non-staged location. This is happening because the staged shims’ install names were needlessly set to their non-staged locations.
Created attachment 269650 [details]
Have the install name match the install path in staged installs
Fixed in <http://trac.webkit.org/r195505>.
Now I know that you type my name by hand :-0