Debugging and logging php cronjobs

timeout -s9 1h php -d memory_limit=4096M run-action.php --host=www.goodbuys.ca --action=import_hook --lock=import;

Every time I run this, I get:

Exception detail: /var/log/goodbuys/goodbuys-goodbuys-exp_30272b7e17.json
Class: gb\php\PHPErrorException
Line: 12

Documentation Link: No Documentation
Message: PHP Error #2: Invalid argument supplied for foreach()

====================================
Stack trace:
#0 /home/goodbuys/version/ver/v1.3.131/goodbuys.com/vendor/goodbuys/libraries/gb/php/ErrorHandler.php(35): gb\php\PHPErrorException::create(2, 'Invalid argumen...', '/home/gbvim...', 91)
#1 /home/goodbuys/version/ver/v1.3.131/goodbuys.com/vendor/goodbuys/libraries/gb/thirdparty/gbsolution/InventoryReader.php(91): gb\php\ErrorHandler->handle(2, 'Invalid argumen...', '/home/gbvim...', 91, Array)
#2 /home/goodbuys/version/ver/v1.3.131/goodbuys.com/vendor/goodbuys/libraries/gb/thirdparty/gbsolution/InventoryMsSQLSync.php(70): gb\thirdparty\gbsolution\InventoryReader->getIterator()
#3 /home/goodbuys/version/ver/v1.3.131/goodbuys.com/scripts/run-resource.php(50): gb\thirdparty\gbsolution\InventoryMsSQLSync->run()
#4 {main}

I keep getting errors, but when I put print_r() inside InventoryReader.php and InventoryMsSQLSync.php, I don't get anything, even if I add > debug.log at the end. Is there a way to print everything?

I put the print_r() before the error, and still I don't get anything. I want to print the logs on the console.