When used with the version of Buildbot mentioned in the wiki pages, the WebKit configuration results in an exception about RemoteShellCommand having no log attribute. build.webkit.org isn't showing this as it has had its configuration updated to handle this situation. The new configuration should be in SVN.
Created attachment 10568 [details] Patch
Created attachment 10583 [details] Patch
Comment on attachment 10583 [details] Patch Looks fine
Landed in r16383.