pestphp/pest · error · InvalidOption

The [--process-isolation] option is not supported.

Error message

The [--process-isolation] option is not supported.

What it means

Error "The [--process-isolation] option is not supported." thrown in pestphp/pest.

Source

Thrown at src/Plugins/ProcessIsolation.php:23

namespace Pest\Plugins;

use Pest\Contracts\Plugins\HandlesArguments;
use Pest\Exceptions\InvalidOption;

/**
 * @internal
 */
final class ProcessIsolation implements HandlesArguments
{
    use Concerns\HandleArguments;

    /**
     * {@inheritDoc}
     */
    public function handleArguments(array $arguments): array
    {
        if ($this->hasArgument('--process-isolation', $arguments)) {
            throw new InvalidOption('The [--process-isolation] option is not supported.');
        }

        return $arguments;
    }
}

View on GitHub (pinned to 1af74a215c)

When it happens

Trigger: Thrown at src/Plugins/ProcessIsolation.php:23 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of pestphp/pest@1af74a215c (2026-08-21). Data as JSON: /api/errors/0946f70ad800f9e1. Report an issue: GitHub.