How to debug updating an instance variable of a php Trait without using setters

Background

I'm trying to use the leeway property of jwt-auth as recommended here to circumvent weird timezone differences.

The code in jwt is pretty straight forward, A DateTimeTrait trait is used, at first with an instance variable called leeway:

trait DatetimeTrait
{
    /**
     * Time leeway in seconds.
     *
     * @var int
     */
    protected $leeway = 0;

later on this helper method is used to determine if a given timestamp is in the future:

/**
 * Determine whether the value is in the future.
 *
 * @param  mixed  $value
 *
 * @return bool
 */
protected function isFuture($value)
{
    return Utils::isFuture($value, $this->leeway);
}

I was going over the code, and I realized that the value of leeway changes randomly. At some point I figured we're calling different trait classes so i used the spl_object_hash to know if we're using the same object, it turns out we do:

public function setLeeway($leeway)
{
    $this->leeway = $leeway;
    var_dump("set leeway: ".$this->leeway." on object: ".spl_object_hash($this));

    return $this;
}


protected function isFuture($value)
{
    var_dump("calling is future with leeway :".$this->leeway. " on object: ".spl_object_hash($this));
    return Utils::isFuture($value, $this->leeway);
}

but see the logs:

 string(60) "set leeway: 5000 on object: <obj-hash-1>"
 /vendor/tymon/jwt-auth/src/Claims/DatetimeTrait.php:97:
 string(60) "set leeway: 5000 on object: <obj-hash-2>"
 /vendor/tymon/jwt-auth/src/Claims/DatetimeTrait.php:71:
 string(76) "calling is future with leeway :0 on object: <obj-hash-1>"

where:

• <obj-hash-1> is 000000007386f4100000000038d49b05
• <obj-hash-2> is 000000007386f4160000000038d49b05

Question

How it possible for the same trait to sometimes have the same instance variable 0, and then 500, without that instance variable being updated using a setter? How can I at least debug that property being updated (if it's not done through a setter)

via Chebli Mohamed