Created attachment 33923 [details] Crash report Startup crash, 10.4 Intel; unhelpful overview details below, complete (and still not very helpful, with that stack) in the attachment: Exception: EXC_BAD_ACCESS (0x0001) Codes: KERN_PROTECTION_FAILURE (0x0002) at 0x0000003d Thread 0 Crashed: 0 com.apple.Safari 0x00002613 0x1000 + 5651 1 com.apple.Safari 0x000f260e 0x1000 + 988686 2 com.apple.Safari 0x000023dd 0x1000 + 5085 Thread 1: 0 libSystem.B.dylib 0x90024407 semaphore_wait_signal_trap + 7 1 com.apple.JavaScriptCore 0x0057a6e8 WTF::TCMalloc_PageHeap::scavengerThread() + 552 2 com.apple.JavaScriptCore 0x0057a721 WTF::TCMalloc_PageHeap::runScavengerThread(void*) + 17 3 libSystem.B.dylib 0x90023d67 _pthread_body + 84 Regression range is 46507 nightly works, 46631 nightly fails.
*** This bug has been marked as a duplicate of bug 27900 ***