奇怪的错误：This generally means that another instance of this process was already running or is hung in t

真机调试，好好的突然收到如下gdb错误：

This generally means that another instance of this process was already running or is hung in the debugger

重启Xcode没用，Clean没用，重启系统没用，拔线重插没用，唯一有用的就是关闭iPhone重启。至今不知道什么原因。