The failing test is Source/JavaScriptCore/tests/mozilla/js1_5/Array/regress-157652.js. This is flaky, and I couldn't ever get it to happen inside lldb or in Release mode. while true; do DYLD_FRAMEWORK_PATH=jsc.deb/ jsc.deb/jsc --useFTLJIT\=false --enableFunctionDotArguments\=true --useFTLJIT\=true --ftlCrashesIfCantInitializeLLVM\=true shell.js regress-157652.js --useDFGJIT=0 --useLLInt=0; done BUGNUMBER: 157652 STATUS: Testing that Array.sort() doesn't crash on very large arrays BUGNUMBER: 157652 STATUS: Testing that Array.sort() doesn't crash on very large arrays BUGNUMBER: 157652 STATUS: Testing that Array.sort() doesn't crash on very large arrays BUGNUMBER: 157652 STATUS: Testing that Array.sort() doesn't crash on very large arrays BUGNUMBER: 157652 STATUS: Testing that Array.sort() doesn't crash on very large arrays BUGNUMBER: 157652 STATUS: Testing that Array.sort() doesn't crash on very large arrays BUGNUMBER: 157652 STATUS: Testing that Array.sort() doesn't crash on very large arrays Segmentation fault: 11 BUGNUMBER: 157652 STATUS: Testing that Array.sort() doesn't crash on very large arrays Segmentation fault: 11