23 tests are crashing on Mac Debug after the changes in https://trac.webkit.org/changeset/254491/webkit It looks like the new Assert is causing this. Example crash log: stderr: ASSERTION FAILED: heap.mutatorState() != MutatorState::Running ./runtime/VM.cpp(1069) : void JSC::VM::scanSideState(JSC::ConservativeRoots &) const 1 0x7524c3c39 WTFCrash 2 0x752c0461b WTFCrashWithInfo(int, char const*, char const*, int) Results: https://build.webkit.org/results/Apple-Catalina-Debug-WK2-Tests/r254491%20(1674)/results.html build: https://build.webkit.org/builders/Apple-Catalina-Debug-WK2-Tests/builds/1674
<rdar://problem/58567209>
Fixed in r254549: <https://trac.webkit.org/changeset/254549>