Flarum\Install\Prerequisite\PhpVersion::check PHP Method

    public function check()
    {
        if (version_compare(PHP_VERSION, '5.5.0', '<')) {
            $this->errors[] = ['message' => "PHP {$this->minVersion} is required.", 'detail' => 'You are running version ' . PHP_VERSION . '. Talk to your hosting provider about upgrading to the latest PHP version.'];
        }
    }