This is the process command I have to execute, The argument contactIds is an array.
$process = new Process([
"php",
"../fairgate4/bin/console",
"contactlist:remove",
$contactIds // array
]);
$process->start();
Symfony throws an error for this argument :
Argument 1 passed to Symfony\Component\Process\Process::escapeArgument() must be of the type string or null, array given