Fatal error: Class 'Symfony\Component\Process\Tests\AbstractProcessTest' not found in /var/www/html/dev/spa/vendor/symfony/process/Symfony/Component/Process/Tests/SigchildEnabledProcessTest.php on line 15

Call Stack:
    0.0005     251344   1. {main}() /var/www/html/dev/spa/vendor/symfony/process/Symfony/Component/Process/Tests/SigchildEnabledProcessTest.php:0