What is the difference?

casperTest.php

<?php
/**
 * The Gearman Worker script
 */ 

$worker= new GearmanWorker();
$worker->addServer();
$worker->addFunction("LayoutbooksAssembler", "sendToCasper");
while ($worker->work());

function sendToCasper($job) {

    echo "whoami you ask? ";
    $processUser = posix_getpwuid(posix_geteuid());
    print $processUser['name'];
    echo "!\r\n\r\n";

    $jobParams = (array) json_decode($job->workload());

    exec("phantomjs --version",$output);
    var_dump($output); //got the phantomjs version (2.1)

    //everything thus far is rendered to screen or logged just fine when worker is initiated via CLI *or* supervisord
    //but if started from supervisord, the casperjs process below hangs (phantomjs takes 99% CPU until killed) and nothing in a casper script runs
    exec("casperjs --version",$moreOutput)
    var_dump($moreOutput); //will never get here if gearman worker is started from anything but CLI
}

php run from cli:

/usr/bin/php /var/www/xmweb/gearman_client_tests/casperTest.php

supervisord.conf

[program:casperWorker]
command=/usr/bin/php /var/www/xmweb/gearman_client_tests/casperTest.php
process_name=casperWorker
numprocs=1
user=vagrant
environment=GEARMAN_USER="vagrant"
stopsignal=KILL
autostart=true
autorestart=true
stdout_logfile=/home/vagrant/gearmanLogs/casper.log
stderr_logfile=/home/vagrant/gearmanLogs/casper_errors.log

phantomJS version: 2.1
casperJS version: 1.1-beta5

When initiating my worker from the CLI, all is great... when I try to initiate it via supervisord, phantomjs/casperjs hang indefinitely, use 99.7% cpu and the casper script does not run... though all the other stuff before the command does run. The worker sees itself as "vagrant" when started via CLI or supervisord; even a simple 'casperjs --version' will cause casperjs to hang when run from supervisord, unlike 'phantomjs --version' (both will run fine when started via CLI)

WHAT IS HAPPENING!!! Any tips appreciated, ultimately I need these worker scripts to start via supervisord!