Bootloader Version...: angler-03.84

Baseband Version.....: angler-03.88

Serial Number........: 

--------------------------------------------

extracting android-info.txt (0 MB) to RAM...

Checking 'product'                                OKAY [  0.020s]

Checking 'version-bootloader'                      OKAY [  0.021s]

Checking 'version-baseband'                        OKAY [  0.020s]

Snapshot cancel                                    FAILED (remote: 'unknown command')

fastboot: error: Command failed

是因为安装的android sdk中的platform-tools版本过高。

因此需要下载低于或者等于版本26的platform-tools暂时替换掉新版的platform-tools。