The following map related JSC tests are constant failures on BigSur debug and higher: jsc-layout-tests.yaml/js/script-tests/basic-map.js.layout jsc-layout-tests.yaml/js/script-tests/basic-map.js.layout-dfg-eager-no-cjit jsc-layout-tests.yaml/js/script-tests/basic-map.js.layout-ftl-eager-no-cjit jsc-layout-tests.yaml/js/script-tests/basic-map.js.layout-ftl-no-cjit jsc-layout-tests.yaml/js/script-tests/basic-map.js.layout-no-cjit jsc-layout-tests.yaml/js/script-tests/basic-map.js.layout-no-ftl jsc-layout-tests.yaml/js/script-tests/basic-map.js.layout-no-llint jsc-layout-tests.yaml/js/script-tests/basic-set.js.layout jsc-layout-tests.yaml/js/script-tests/basic-set.js.layout-dfg-eager-no-cjit jsc-layout-tests.yaml/js/script-tests/basic-set.js.layout-ftl-eager-no-cjit jsc-layout-tests.yaml/js/script-tests/basic-set.js.layout-ftl-no-cjit jsc-layout-tests.yaml/js/script-tests/basic-set.js.layout-no-cjit jsc-layout-tests.yaml/js/script-tests/basic-set.js.layout-no-ftl jsc-layout-tests.yaml/js/script-tests/basic-set.js.layout-no-llint jsc-layout-tests.yaml/js/script-tests/map-grow-with-holes.js.layout jsc-layout-tests.yaml/js/script-tests/map-grow-with-holes.js.layout-dfg-eager-no-cjit jsc-layout-tests.yaml/js/script-tests/map-grow-with-holes.js.layout-ftl-eager-no-cjit jsc-layout-tests.yaml/js/script-tests/map-grow-with-holes.js.layout-ftl-no-cjit jsc-layout-tests.yaml/js/script-tests/map-grow-with-holes.js.layout-no-cjit jsc-layout-tests.yaml/js/script-tests/map-grow-with-holes.js.layout-no-ftl jsc-layout-tests.yaml/js/script-tests/map-grow-with-holes.js.layout-no-llint jsc-layout-tests.yaml/js/script-tests/symbol-in-map.js.layout jsc-layout-tests.yaml/js/script-tests/symbol-in-map.js.layout-dfg-eager-no-cjit jsc-layout-tests.yaml/js/script-tests/symbol-in-map.js.layout-ftl-eager-no-cjit jsc-layout-tests.yaml/js/script-tests/symbol-in-map.js.layout-ftl-no-cjit jsc-layout-tests.yaml/js/script-tests/symbol-in-map.js.layout-no-cjit jsc-layout-tests.yaml/js/script-tests/symbol-in-map.js.layout-no-ftl jsc-layout-tests.yaml/js/script-tests/symbol-in-map.js.layout-no-llint microbenchmarks/map-rehash.js.bytecode-cache microbenchmarks/map-rehash.js.default microbenchmarks/map-rehash.js.dfg-eager microbenchmarks/map-rehash.js.dfg-eager-no-cjit-validate microbenchmarks/map-rehash.js.eager-jettison-no-cjit microbenchmarks/map-rehash.js.ftl-eager microbenchmarks/map-rehash.js.ftl-eager-no-cjit-b3o1 microbenchmarks/map-rehash.js.ftl-no-cjit-b3o0 microbenchmarks/map-rehash.js.ftl-no-cjit-no-inline-validate microbenchmarks/map-rehash.js.ftl-no-cjit-no-put-stack-validate microbenchmarks/map-rehash.js.ftl-no-cjit-small-pool microbenchmarks/map-rehash.js.ftl-no-cjit-validate-sampling-profiler microbenchmarks/map-rehash.js.lockdown microbenchmarks/map-rehash.js.mini-mode microbenchmarks/map-rehash.js.no-cjit-validate-phases microbenchmarks/map-rehash.js.no-ftl microbenchmarks/map-rehash.js.no-llint slowMicrobenchmarks.yaml/slowMicrobenchmarks/large-map-iteration-with-mutation.js.ftl-no-cjit-validate-sampling-profiler stress/bigint-and-map-set.js.bytecode-cache stress/bigint-and-map-set.js.default stress/bigint-and-map-set.js.dfg-eager stress/bigint-and-map-set.js.dfg-eager-no-cjit-validate stress/bigint-and-map-set.js.eager-jettison-no-cjit stress/bigint-and-map-set.js.ftl-eager stress/bigint-and-map-set.js.ftl-eager-no-cjit-b3o1 stress/bigint-and-map-set.js.ftl-no-cjit-b3o0 stress/bigint-and-map-set.js.ftl-no-cjit-no-inline-validate stress/bigint-and-map-set.js.ftl-no-cjit-no-put-stack-validate stress/bigint-and-map-set.js.ftl-no-cjit-small-pool stress/bigint-and-map-set.js.ftl-no-cjit-validate-sampling-profiler stress/bigint-and-map-set.js.lockdown stress/bigint-and-map-set.js.mini-mode stress/bigint-and-map-set.js.no-cjit-validate-phases stress/bigint-and-map-set.js.no-ftl stress/bigint-and-map-set.js.no-llint stress/elidable-new-object-roflcopter-then-exit.js.lockdown stress/map-cse-correctness.js.bytecode-cache stress/map-cse-correctness.js.default stress/map-cse-correctness.js.dfg-eager stress/map-cse-correctness.js.dfg-eager-no-cjit-validate stress/map-cse-correctness.js.eager-jettison-no-cjit stress/map-cse-correctness.js.ftl-eager stress/map-cse-correctness.js.ftl-eager-no-cjit-b3o1 stress/map-cse-correctness.js.ftl-no-cjit-b3o0 stress/map-cse-correctness.js.ftl-no-cjit-no-inline-validate stress/map-cse-correctness.js.ftl-no-cjit-no-put-stack-validate stress/map-cse-correctness.js.ftl-no-cjit-small-pool stress/map-cse-correctness.js.ftl-no-cjit-validate-sampling-profiler stress/map-cse-correctness.js.lockdown stress/map-cse-correctness.js.mini-mode stress/map-cse-correctness.js.no-cjit-validate-phases stress/map-cse-correctness.js.no-ftl stress/map-cse-correctness.js.no-llint stress/map-delete.js.lockdown stress/map-iteration.js.bytecode-cache stress/map-iteration.js.default stress/map-iteration.js.dfg-eager stress/map-iteration.js.dfg-eager-no-cjit-validate stress/map-iteration.js.eager-jettison-no-cjit stress/map-iteration.js.ftl-eager stress/map-iteration.js.ftl-eager-no-cjit-b3o1 stress/map-iteration.js.ftl-no-cjit-b3o0 stress/map-iteration.js.ftl-no-cjit-no-inline-validate stress/map-iteration.js.ftl-no-cjit-no-put-stack-validate stress/map-iteration.js.ftl-no-cjit-small-pool stress/map-iteration.js.ftl-no-cjit-validate-sampling-profiler stress/map-iteration.js.lockdown stress/map-iteration.js.mini-mode stress/map-iteration.js.no-cjit-validate-phases stress/map-iteration.js.no-ftl stress/map-iteration.js.no-llint stress/map-rehash-2.js.bytecode-cache stress/map-rehash-2.js.default stress/map-rehash-2.js.dfg-eager stress/map-rehash-2.js.eager-jettison-no-cjit stress/map-rehash-2.js.ftl-eager stress/map-rehash-2.js.ftl-no-cjit-b3o0 stress/map-rehash-2.js.ftl-no-cjit-no-inline-validate stress/map-rehash-2.js.ftl-no-cjit-no-put-stack-validate stress/map-rehash-2.js.ftl-no-cjit-small-pool stress/map-rehash-2.js.ftl-no-cjit-validate-sampling-profiler stress/map-rehash-2.js.lockdown stress/map-rehash-2.js.mini-mode stress/map-rehash-2.js.no-cjit-validate-phases stress/map-rehash-2.js.no-ftl stress/map-rehash-2.js.no-llint stress/map-rehash.js.bytecode-cache stress/map-rehash.js.default stress/map-rehash.js.dfg-eager stress/map-rehash.js.ftl-eager stress/map-rehash.js.ftl-eager-no-cjit-b3o1 stress/map-rehash.js.ftl-no-cjit-validate-sampling-profiler stress/map-rehash.js.lockdown stress/map-rehash.js.mini-mode stress/map-rehash.js.no-ftl stress/map-rehash.js.no-llint stress/modify-map-during-iteration.js.bytecode-cache stress/modify-map-during-iteration.js.default stress/modify-map-during-iteration.js.dfg-eager stress/modify-map-during-iteration.js.dfg-eager-no-cjit-validate stress/modify-map-during-iteration.js.eager-jettison-no-cjit stress/modify-map-during-iteration.js.ftl-eager stress/modify-map-during-iteration.js.ftl-eager-no-cjit-b3o1 stress/modify-map-during-iteration.js.ftl-no-cjit-b3o0 stress/modify-map-during-iteration.js.ftl-no-cjit-no-inline-validate stress/modify-map-during-iteration.js.ftl-no-cjit-no-put-stack-validate stress/modify-map-during-iteration.js.ftl-no-cjit-small-pool stress/modify-map-during-iteration.js.ftl-no-cjit-validate-sampling-profiler stress/modify-map-during-iteration.js.lockdown stress/modify-map-during-iteration.js.mini-mode stress/modify-map-during-iteration.js.no-cjit-validate-phases stress/modify-map-during-iteration.js.no-ftl stress/modify-map-during-iteration.js.no-llint stress/modify-set-during-iteration.js.bytecode-cache stress/modify-set-during-iteration.js.default stress/modify-set-during-iteration.js.dfg-eager stress/modify-set-during-iteration.js.dfg-eager-no-cjit-validate stress/modify-set-during-iteration.js.eager-jettison-no-cjit stress/modify-set-during-iteration.js.ftl-eager stress/modify-set-during-iteration.js.ftl-eager-no-cjit-b3o1 stress/modify-set-during-iteration.js.ftl-no-cjit-b3o0 stress/modify-set-during-iteration.js.ftl-no-cjit-no-inline-validate stress/modify-set-during-iteration.js.ftl-no-cjit-no-put-stack-validate stress/modify-set-during-iteration.js.ftl-no-cjit-small-pool stress/modify-set-during-iteration.js.ftl-no-cjit-validate-sampling-profiler stress/modify-set-during-iteration.js.lockdown stress/modify-set-during-iteration.js.mini-mode stress/modify-set-during-iteration.js.no-cjit-validate-phases stress/modify-set-during-iteration.js.no-ftl stress/modify-set-during-iteration.js.no-llint History is easiest to observe by looking at the test runs here: https://build.webkit.org/#/builders/378
<rdar://problem/104677541>
Other tests that started to fail at the same point, but don't appear to reference maps or set in their name are as follows: airjs-tests.yaml/stress-test.js.bytecode-cache airjs-tests.yaml/stress-test.js.default airjs-tests.yaml/stress-test.js.dfg-eager airjs-tests.yaml/stress-test.js.dfg-eager-no-cjit-validate airjs-tests.yaml/stress-test.js.eager-jettison-no-cjit airjs-tests.yaml/stress-test.js.ftl-eager airjs-tests.yaml/stress-test.js.ftl-eager-no-cjit-b3o1 airjs-tests.yaml/stress-test.js.ftl-no-cjit-b3o0 airjs-tests.yaml/stress-test.js.ftl-no-cjit-no-inline-validate airjs-tests.yaml/stress-test.js.ftl-no-cjit-no-put-stack-validate airjs-tests.yaml/stress-test.js.ftl-no-cjit-small-pool airjs-tests.yaml/stress-test.js.ftl-no-cjit-validate-sampling-profiler airjs-tests.yaml/stress-test.js.mini-mode airjs-tests.yaml/stress-test.js.no-cjit-validate-phases airjs-tests.yaml/stress-test.js.no-ftl airjs-tests.yaml/stress-test.js.no-llint wasm.yaml/wasm/v8/many-memories-no-trap-handler.js.wasm-eager-jettison
While there is a fairly large range in-between test runs, with the most recent pass occurring at 259088@main, and the first failure occurring at the next test run after that which was 259117@main. It does appear that 259117@main does modify map and set: https://commits.webkit.org/259117@main I would think that would be a likely culprit?
For some reason a new bug was filed to land the fix. *** This bug has been marked as a duplicate of bug 251191 ***