Just saw jsc-layout-tests.yaml/js/script-tests/dfg-create-inlined-arguments-in-closure-inline.js.layout-no-llint fail on a bot jsc-layout-tests.yaml/js/script-tests/dfg-create-inlined-arguments-in-closure-inline.js.layout-no-llint: Tests that if the DFG tries to create inlined arguments from within a inlined call frame corresponding to a closure call, then we don't crash. jsc-layout-tests.yaml/js/script-tests/dfg-create-inlined-arguments-in-closure-inline.js.layout-no-llint: jsc-layout-tests.yaml/js/script-tests/dfg-create-inlined-arguments-in-closure-inline.js.layout-no-llint: On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE". jsc-layout-tests.yaml/js/script-tests/dfg-create-inlined-arguments-in-closure-inline.js.layout-no-llint: jsc-layout-tests.yaml/js/script-tests/dfg-create-inlined-arguments-in-closure-inline.js.layout-no-llint: jsc-layout-tests.yaml/js/script-tests/dfg-create-inlined-arguments-in-closure-inline.js.layout-no-llint: test_script_6725: line 2: 1698 Segmentation fault: 11 "$@" ../../../../.vm/JavaScriptCore.framework/Resources/jsc --useLLInt\=false resources/standalone-pre.js dfg-create-inlined-arguments-in-closure-inline.js resources/standalone-post.js jsc-layout-tests.yaml/js/script-tests/dfg-create-inlined-arguments-in-closure-inline.js.layout-no-llint: ERROR: Unexpected exit code: 139 FAIL: jsc-layout-tests.yaml/js/script-tests/dfg-create-inlined-arguments-in-closure-inline.js.layout-no-llint http://build.webkit.org/builders/Apple%20MountainLion%20Debug%20WK1%20(Tests)/builds/12557/steps/jscore-test/logs/stdio I don't have any information about how frequently this happens.