kohana/minion — pull request #100 by cyrgit (2014-10-31 12:19:14+00:00)
Title: Call to is_subclass_of() expects a string

Using the class name directly throws an exception:

ErrorException [ 8 ]: Use of undefined constant Minion_Task - assumed 'Minion_Task'

Verified by looking at PHP source directly which confirms this should a string:

ZEND_PARSE_PARAMETERS_START(2, 3)
Z_PARAM_ZVAL(obj)
Z_PARAM_STR(class_name)
Z_PARAM_OPTIONAL
Z_PARAM_BOOL(allow_string)
ZEND_PARSE_PARAMETERS_END();

Notice only the first argument is a zval, $class_name is a string.