The fast-unwind implementation of leak-sanitizer will obtain the current stack top/bottom and frame address(Stack Pointer) for backtrace calculation: https://github.com/gcc-mirror/gcc/blob/releases/gcc-13/libsanitizer/lsan/lsan.cpp#L39-L42 Since the scheduling mechanism of NuttX sim is coroutine (setjmp/longjmp), if the Stack Pointer is switched, the fast-unwind will unable to get the available address, so the memory leaks on the system/application side that cannot be caught normally. This PR will disable fast-unwind by default to avoid unwind failure. Signed-off-by: chao an <anchao@xiaomi.com>