i use my linux box (RH6.1) to debug some multi-thread programs. when i created the new thread,and make it suspend, then i want to trace it,i use the gdb 4.18 . but when i use attach command, it tells me: "Error: ptrace: Operation not permitted." it seems the gdb4.18 DOSE NOT support multi-thread,i'm not sure. how to get a correct gdb version so i can debug my threads?