PHP Fatal error Call to undefined method fromShellCommandline

[filipecsweb]

Hi.

Error:

PHP Fatal error:  Uncaught Error: Call to undefined method Symfony\Component\Process\Process::fromShellCommandline() in /var/www/html/vendor/spatie/image-optimizer/src/OptimizerChain.php:97

I'm getting the error above when using the following code:

$optimizer = (new OptimizerChain())
    ->addOptimizer(
        new Jpegoptim([
            '-m80'
            '--strip-all',
            '--all-progressive',
            '--quiet',
        ])
    );

$optimizer
    ->optimize('image.jpg');

I'm running spatie/image-optimizer 1.6.

Also, oddly I could fix it changing the code to:

$optimizer = (new OptimizerChain())
    ->addOptimizer(
        new Jpegoptim([
            '-m80'
            '--strip-all',
            '--all-progressive',
            '--quiet',
        ])
    );

// Composer autoload should be loading this file but it seems it's not...
require_once __DIR__ . '/vendor/symfony/process/Process.php';

$optimizer
    ->optimize('image.jpg');

Dou you know why?
Could someone please help?