在用真机运行 appium 进行测试时，最近老是提示 app 没有安装，但有时能够提示 app 已经安装了。
目前 fruitstrap 命令也变的不稳定了么？
请问大家有遇到这样的问题吗？
如下，第一次就可以提示 app is installed
第二次就提示错误，说是 app 没有安装。

pptest1tekiMac-10:~ pptest1$ sudo /usr/local/lib/node_modules/appium/build/fruitstrap/fruitstrap isInstalled --id a0ee9c874742cdd4bef1b43f148fe72068c58265 --bundle com.25pp.ppappinstaller2
[....] Waiting for iOS device to be connected
found device id
found device id
[  0%] Found device (a0ee9c874742cdd4bef1b43f148fe72068c58265), beginning check
App is installed!
[100%] Check completed com.25pp.ppappinstaller2
pptest1tekiMac-10:~ pptest1$ sudo /usr/local/lib/node_modules/appium/build/fruitstrap/fruitstrap isInstalled --id a0ee9c874742cdd4bef1b43f148fe72068c58265 --bundle com.25pp.ppappinstaller2
[....] Waiting for iOS device to be connected
found device id
[  0%] Found device (a0ee9c874742cdd4bef1b43f148fe72068c58265), beginning check
App is installed!
Assertion failed: (AMDeviceStartService(device, CFSTR("com.apple.afc"), &afcFd, NULL) == 0), function handle_device, file fruitstrap.c, line 523.