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。