Fatal error: Uncaught Error: Undefined constant "STDIN" in C:\xampp\htdocs\r10csm\vendor\symfony\process\Tests\PipeStdinInStdoutStdErrStreamSelect.php:17 Stack trace: #0 {main} thrown in C:\xampp\htdocs\r10csm\vendor\symfony\process\Tests\PipeStdinInStdoutStdErrStreamSelect.php on line 17