op_msg_fuzzer invokes a large body of code, which may use logging. Because log message include thread names stored in thread local variables, logging uses thread local state. libfuzzer binaries do not have hooks into global shutdown. The only way to cleanly tear down state is to declare a global static destructor. These destructors run after thread local variables are destroyed. Accessing thread local variables in a destructor is UB. op_msg_fuzzer uses systems which log in shutdown. Thus, we should turn off logging.