Since we added the jsHeapLimitMB setParameter, it's possible to make the javascript engine run out of memory before it is able to initialize a JSContext. Because the OOM handling of our custom allocator needs a pointer to the scope to mark it as OOM, this can cause the server to abort. We need to make sure the server doesn't crash when this happens and issue an appropriate warning that the jsHeapLimitMB is too low to actually run any javascript.