http://build.webkit.org/builders/Lion%20Release%20%28Perf%29/builds/2105/steps/perf-test/logs/stdio It seems like someone completely broke DRT for the purpose of running perf tests.
Oops, it was me (http://trac.webkit.org/changeset/113651) :( mrowe fixed it in http://trac.webkit.org/changeset/113920. Thanks!