Error from Google API PHP Config.php file - Fatal Error - Call to undefined function sys_get_temp_dir()

Question

The Google API PHP Client library has a file named Config.php. I'm getting an error from that file, from line 139.

'directory' => sys_get_temp_dir() . '/Google_Client'

The error is:

Fatal error: Call to undefined function sys_get_temp_dir() in C:\Users\NoName\Documents\academic-being-90217\google-api-php-client\src\Google\Config.php on line 139

Here is a link to the file in GitHub:

GitHub file - Config.php

Why am I getting that error?

Do I need to create a temp directory? There is no temp directory defined.

The PHP function sys_get_temp_dir()

Returns the path of the directory PHP stores temporary files in by default

I'm running this code from Google App Engine Launcher on my computer. Does that make a difference, as opposed to running it from the host server?

I created a temp directory under google-api-php-client/src/Google but that didn't stop the error.

I'm beginning to wonder if this is an internal issue with Google App Engine Launcher, and whether the sys_get_temp_dir() function is available to it.

If all I do is run just one line of code:

<?php

  $thisIsATest = sys_get_temp_dir();
  return;

I get the same error. So that error has nothing to do with any other part of the code.

I guess that I could hard code a directory path, and make sure there is a folder there to be available to use.

'directory' => 'src/Google/temp/Google_Client'

Well, if I hard code a directory path for that line, I don't get an error any more. But I'm not sure I've got the path set up correctly.