执行click操作时，UIAutomatorWD server一直自动重启

File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/macaca/webelement.py", line 381, in click
self._execute(Command.CLICK_ELEMENT)
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/macaca/webelement.py", line 60, in _execute
return self._driver._execute(command, data, unpack)
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/macaca/webdriver.py", line 68, in _execute
ret.raise_for_status()
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/macaca/webdriverresult.py", line 54, in raise_for_status
raise WebDriverException(error, message, screen, stacktrace)
macaca.webdriverexception.WebDriverException:
Error: WebDriverError.UNKNOWN_ERROR

macaca-doctor version: 2.0.3

Node.js checklist:

node env: /usr/local/bin/node
node version: v6.10.3

iOS checklist:

Xcode Command Line Tools is ready, version: 2347.
{ Error: Command failed: xcodebuild -version
xcode-select: error: tool 'xcodebuild' requires Xcode, but active developer directory '/Library/Developer/CommandLineTools' is a command line tools instance

at ChildProcess.exithandler (child_process.js:204:12)
at emitTwo (events.js:106:13)
at ChildProcess.emit (events.js:191:7)
at maybeClose (internal/child_process.js:886:16)
at Socket. (internal/child_process.js:342:11)
at emitOne (events.js:96:13)
at Socket.emit (events.js:188:7)
at Pipe._handle.close [as _onclose] (net.js:497:12)
killed: false,
code: 1,
signal: null,
cmd: 'xcodebuild -version' }
Xcode is uninstalled
iproxy[usbmuxd] is installed at: `/usr/local/bin/iproxy`
ios_webkit_debug_proxy is installed at: `/usr/local/bin/ios_webkit_debug_proxy`
carthage is installed, version: 0.23.0

Android checklist:

JAVA version is `1.8.0_111`
JAVA_HOME is set to `/Library/Java/JavaVirtualMachines/jdk1.8.0_111.jdk/Contents/Home`
ANDROID_HOME is set to `/Users/lxxxx/Library/Android/sdk`
Platforms is set to `/Users/lxxxx/Library/Android/sdk/platforms/android-25`
ADB tool is set to `/Users/lxxxx/Library/Android/sdk/platform-tools/adb`
gradle is installed, version: 3.5

Installed driver list:

android: 2.0.40
chrome: 1.0.7
electron: 1.1.17

Start with the click traceback in macaca/webelement.py and follow _execute through macaca/webdriver.py and macaca/webdriverresult.py. Run macaca-doctor and inspect the UIAutomatorWD server output while reproducing the click; done means the click completes without the server restarting, with the missing environment details and failure cause documented.

Written by the indexing model from the issue text.