Unclear exception message in Symfony\Component\PropertyAccess\Exception\AccessException;

[Holicz]

Symfony version(s) affected: >= 3.4

Description
When PHP 7.4 typed property is accessed in form before initialization Symfony throws an exception with a message The property "App\Form\Model\ContactFormModel::$firstName" is not readable because it is typed "string". You should either initialize it or make it nullable using "?string" instead. which is entirely not true.

If I have this in my model:

/**
 * @Assert\NotBlank
 */
public string $firstname;

And will make it this according to the message:

/**
 * @Assert\NotBlank
 */
public ?string $firstname;

The error is still there since I need to make it this

/**
 * @Assert\NotBlank
 */
public ?string $firstname = null;

How to reproduce
Create a model with below code, use it in a form, render the form and try to fix the error by the exception message instructions.

/**
 * @Assert\NotBlank
 */
public string $firstname;

Possible Solution
Improve the error message, I will provide the PR. What do you think about The property "App\Form\Model\ContactFormModel::$firstName" is not readable because it is typed "string". You should either initialize it or make it nullable using "?string" **and initialize it to null** instead.?