This leads to a failure during 'make install'. To fix it just allow that step to fail by using try/except in the python script, patch coming.
Created attachment 163683 [details] Patch
Comment on attachment 163683 [details] Patch Clearing flags on attachment: 163683 Committed r128367: <http://trac.webkit.org/changeset/128367>
All reviewed patches have been landed. Closing bug.