Could not open input file when spawning multiple php scripts

Hello,

I am building a project that involves launching PHP script concurrently (between 3-4). When I launch only one script with
`Porcelain.spawn("php", [Script.php_slave(job.worker_version), boot, "#{environment_id}"], in: :receive, out: {:send, OutputManager.where_is(environment_id)})`

it works very well but when I launch this instruction few times I have the output:
`Could not open input file: /Users/test/tasky/worker_umbrella/apps/worker/libraries/v1/tasky-php/scripts/slave.php`

Is there an option or a limit in the spawning?

Thanks for your feedback