使用xdebug_start_trace（）和xdebug_stop_trace（）时，Xdebug默认保存文件在哪里？

I have just installed Xdebug on Linux, and I have used this functions in a PHP script:

xdebug_stack_trace();
//some php code
xdebug_stop_trace()

It is suppossed a file is saved somewhere in filesystem with the functions called between those two Xdebug functions, but I can not find it..

I have checked that Xdebug is installed and enabled.

string xdebug_start_trace( [ string trace_file [, integer options] ] )

Starts a new function trace

Start tracing function calls from this point to the file in the trace_file parameter.

If no filename is given, then the trace file will be placed in the directory as configured by the xdebug.trace_output_dir setting.

xdebug.trace_output_dir

Type: string, Default value: /tmp

Look in /tmp

See more on: https://xdebug.org/docs/all_settings#trace_output_dir

Verify writes on /tmp directory:

The directory where the profiler output will be written to, make sure that the user who the PHP will be running as has write permissions to that directory. This setting can not be set in your script with ini_set().