update-webkit fails when the current directory is not inside a Subversion working copy. Prior to r51728, the script worked when invoked from any directory, and updated the working copy.
Created attachment 44372 [details]
Invoke isSVN() in the correct working directory
style-queue ran check-webkit-style on attachment 44372 [details] without any errors.
Fixed in <http://trac.webkit.org/projects/webkit/changeset/51745>
Sorry for the regression. I wish we had tests for these scripts. Thanks for cleaning up after me.