The problem

As per my previous question here, it was pointed out to me that I shouldn't be trying to fill related models in a Laravel Factory (i.e I should fill them in their own factory).

However, I have an observer that looks for the related data during the creation and tries to fill related models (this is so I can create multiple related entities using just the create:: method and a single multistep form). Now, I need to add a check to see if this data is populated in the observer so I don't have to specify it in the factory.

In doing so, I now get a segmentation fault when trying to seed my database. I've narrowed down the cause to this line - without the isset check, it works fine (other than $data['day'] is not specified, hence the check);

Segmentation fault (core dumped)

if(isset($data['day'])) $event->day->fill($data['day']);

Related Code

EventFactory.php

$factory->define(App\Event::class, function (Faker $faker) {
    return [
        "name"                        => "A Test Event",
        "description"                 => $faker->paragraphs(3, true),
        "event_start_date"            => today(),
        "event_opening_date"          => today(),
        "event_closing_date"          => tomorrow(),
        "user_id"                     => 1,
        "banner_id"                   => 1,
        "gallery_id"                  => 1,
        "related_event_id"            => 1,
        "status"                      => "published",
        "purchase_limit"              => 1000,
        "limit_remaining"             => 1000,
        "delivery_method"             => "collection",
        "merchandise_delivery_method" => "collection"
    ];
});

EventObserver.php

public function created($event){
        # get all attributes
        $data = $event->getAttributes();

        # fill any related models
        if(isset($data['day'])) $event->day->fill($data['day']);

        # save user
        $event->push();
    }

public function updating($model){
        # get all attributes
        $data = $model->getAttributes();

        # fill any related models
        if(isset($data['day'])) $model->day->fill($data['day']);

        # save user
        $model->push();
    }

Other Info

Command: sudo php artisan migrate:reset --seed

Host: Windows 10

VM Environment: Vagrant running Ubuntu 16.04 via HyperV, mounted share with Samba

PHP Version: 7.1.20

Laravel Version: 5.7

Update

Turns out the issue is actually with this line;

$event->push();

Could there be something recursive happening here?

Update 2

With Namoshek's help, I can now narrow it down to the following error from xdebug;

Maximum function nesting level of '256' reached, aborting!

Increasing xdebug.max_nesting_level to 200000 brings back the segfault.

This seems to me like it's stuck in an infinite loop. However, I can't see how calling save() or push() in created would end up calling back to itself. Confused.