Fatal error: Uncaught ReflectionException: Class PHPUnit\Framework\Constraint\Constraint does not exist in /var/www/html/simplesamlphp/vendor/symfony/phpunit-bridge/ConstraintTrait.php:16
Stack trace:
#0 /var/www/html/simplesamlphp/vendor/symfony/phpunit-bridge/ConstraintTrait.php(16): ReflectionClass->__construct()
#1 {main}
  thrown in /var/www/html/simplesamlphp/vendor/symfony/phpunit-bridge/ConstraintTrait.php on line 16