Can't understand mount point directories on Windows

Description

The following code:

<?php
var_dump(getcwd());
print_r(scandir("."));

Resulted in this output:

string(16) "R:\dreamflame.in"
PHP Warning:  scandir(.): The system cannot find the path specifi (code: 3) in Command line code on line 2

Warning: scandir(.): The system cannot find the path specifi (code: 3) in Command line code on line 2
PHP Warning:  scandir(.): Failed to open directory: No such file or directory in Command line code on line 2

Warning: scandir(.): Failed to open directory: No such file or directory in Command line code on line 2
PHP Warning:  scandir(): (errno 2): No such file or directory in Command line code on line 2

Warning: scandir(): (errno 2): No such file or directory in Command line code on line 2

But I expected directory listing instead

PHP Version

PHP 8.0.12

Operating System

Windows 11 build 22000

首先，在 Windows 11 上使用 PHP 8.0.12 和报告的路径 R:\dreamflame.in，复现所提供的 getcwd() 和 scandir(".") 示例。将当前目录和目录列表的行为与普通目录进行比较；当 scandir(".") 在没有警告的情况下列出预期内容时，即视为完成。