未找到Google App Engine和Stackdriver调试:/tmp/debugger断点文件

https://cloud.google.com/debugger/docs/setup/php#gae-flex

但是,我的云控制台说应用程序还没有准备好调试,当我浏览到我的应用程序时,我在日志中看到:

PHP Warning:  file_get_contents(/tmp/debugger-breakpoints): failed to open stream: No such 
file or directory in /srv/vendor/google/cloud-debugger/src/BreakpointStorage/FileBreakpointStorage.php on line 94"