Fatal error: Declaration of MockObject_PropertyHookSet_1b26a8f5::$integer::set(?int $value): void must be compatible with Tests\PropertyHookSet::$integer::set(string|int|float|bool|null $value): void in [...]/vendor/phpunit/phpunit/src/Framework/MockObject/Generator/DoubledClass.php(51) : eval()'d code on line 19

<?php
declare(strict_types=1);

namespace Tests;

use PHPUnit\Framework\Attributes\CoversClass;
use PHPUnit\Framework\Attributes\DoesNotPerformAssertions;
use PHPUnit\Framework\TestCase;

class PropertyHookSet {
    public ?int $integer = null {
        get => $this->integer;
        set(string|float|int|bool|null $value) {
            $this->integer = (int)$value;
        }
    }
}

#[CoversClass(PropertyHookSet::class)]
class PhpUnitTest extends TestCase
{
    # Passes as expected
    public function testNormalUsage()
    {
        $propertyHook = new PropertyHookSet();
        $propertyHook->integer = 5;

        $this->assertSame(5, $propertyHook->integer);

        $propertyHook->integer = "5";

        $this->assertSame(5, $propertyHook->integer);
    }

    #Fails with a Fatal error
    #[DoesNotPerformAssertions]
    public function testSomething()
    {
        $mock = $this->createMock(PropertyHookSet::class);
    }
}

doctrine/collections                2.4.0  PHP Doctrine Collections library that adds additional functionality on top of PHP arrays.
doctrine/data-fixtures              2.2.0  Data Fixtures for all Doctrine Object Managers
doctrine/dbal                       4.4.1  Powerful PHP database abstraction layer (DBAL) with many features for database schema introspection and management.
doctrine/deprecations               1.1.5  A small layer on top of trigger_error(E_USER_DEPRECATED) or PSR-3 logging with options to disable all deprecations or selectively for packages.
doctrine/doctrine-bundle            2.18.1 Symfony DoctrineBundle
doctrine/doctrine-fixtures-bundle   3.7.3  Symfony DoctrineFixturesBundle
doctrine/doctrine-migrations-bundle 3.7.0  Symfony DoctrineMigrationsBundle
doctrine/event-manager              2.0.1  The Doctrine Event Manager is a simple PHP event system that was built to be used with the various Doctrine projects.
doctrine/inflector                  2.1.0  PHP Doctrine Inflector is a small library that can perform string manipulations with regard to upper/lowercase and singular/plural forms of words.
doctrine/instantiator               2.0.0  A small, lightweight utility to instantiate objects in PHP without invoking their constructors
doctrine/lexer                      3.0.1  PHP Doctrine Lexer parser library that can be used in Top-Down, Recursive Descent Parsers.
doctrine/migrations                 3.9.5  PHP Doctrine Migrations project offer additional functionality on top of the database abstraction layer (DBAL) for versioning your database schema and easily deploying changes to it. It is a very e...  
doctrine/orm                        3.5.8  Object-Relational-Mapper for PHP
doctrine/persistence                4.1.1  The Doctrine Persistence project is a set of shared interfaces and functionality that the different Doctrine object mappers share.
doctrine/sql-formatter              1.5.3  a PHP SQL highlighting library
dunglas/doctrine-json-odm           1.4.2  An object document mapper for Doctrine ORM using JSON types of modern RDBMS.
egulias/email-validator             4.0.4  A library for validating emails against several RFCs
gglnx/twig-try-catch                1.0.0  Adds exception handling to Twig
masterminds/html5                   2.10.0 An HTML5 parser and serializer.
monolog/monolog                     3.9.0  Sends your logs to files, sockets, inboxes, databases and various web services
myclabs/deep-copy                   1.13.4 Create deep copies (clones) of your objects
nelmio/cors-bundle                  2.6.0  Adds CORS (Cross-Origin Resource Sharing) headers support in your Symfony application
nikic/php-parser                    5.7.0  A PHP parser written in PHP
phar-io/manifest                    2.0.4  Component for reading phar.io manifest information from a PHP Archive (PHAR)
phar-io/version                     3.2.1  Library for handling version information and constraints
phpdocumentor/reflection-common     2.2.0  Common reflection classes used by phpdocumentor to reflect the code structure
phpdocumentor/reflection-docblock   5.6.5  With this component, a library can provide support for annotations via DocBlocks or otherwise retrieve information that is embedded in a DocBlock.
phpdocumentor/type-resolver         1.12.0 A PSR-5 based resolver of Class names, Types and Structural Element Names
phpstan/extension-installer         1.4.3  Composer plugin for automatic installation of PHPStan extensions
phpstan/phpdoc-parser               1.33.0 PHPDoc parser with support for nullable, intersection and generic types
phpstan/phpstan                     2.1.33 PHPStan - PHP Static Analysis Tool
phpstan/phpstan-doctrine            2.0.12 Doctrine extensions for PHPStan
phpstan/phpstan-symfony             2.0.9  Symfony Framework extensions and rules for PHPStan
phpunit/php-code-coverage           12.5.1 Library that provides collection, processing, and rendering functionality for PHP code coverage information.
phpunit/php-file-iterator           6.0.0  FilterIterator implementation that filters files based on a list of suffixes.
phpunit/php-invoker                 6.0.0  Invoke callables with a timeout
phpunit/php-text-template           5.0.0  Simple template engine.
phpunit/php-timer                   8.0.0  Utility class for timing
phpunit/phpunit                     12.5.4 The PHP Unit Testing framework.
psr/cache                           3.0.0  Common interface for caching libraries
psr/clock                           1.0.0  Common interface for reading the clock.
psr/container                       2.0.2  Common Container Interface (PHP FIG PSR-11)
psr/event-dispatcher                1.0.0  Standard interfaces for event handling.
psr/link                            2.0.1  Common interfaces for HTTP links
psr/log                             3.0.2  Common interface for logging libraries
sebastian/cli-parser                4.2.0  Library for parsing CLI options
sebastian/comparator                7.1.3  Provides the functionality to compare PHP values for equality
sebastian/complexity                5.0.0  Library for calculating the complexity of PHP code units
sebastian/diff                      7.0.0  Diff implementation
sebastian/environment               8.0.3  Provides functionality to handle HHVM/PHP environments
sebastian/exporter                  7.0.2  Provides the functionality to export PHP variables for visualization
sebastian/global-state              8.0.2  Snapshotting of global state
sebastian/lines-of-code             4.0.0  Library for counting the lines of code in PHP source code
sebastian/object-enumerator         7.0.0  Traverses array structures and object graphs to enumerate all referenced objects
sebastian/object-reflector          5.0.0  Allows reflection of object attributes, including inherited and non-public ones
sebastian/recursion-context         7.0.1  Provides functionality to recursively process PHP variables
sebastian/type                      6.0.3  Collection of value objects that represent the types of the PHP type system
sebastian/version                   6.0.0  Library that helps with managing the version number of Git-hosted PHP projects
staabm/side-effects-detector        1.0.5  A static analysis tool to detect side effects in PHP code
symfony/asset                       7.4.0  Manages URL generation and versioning of web assets such as CSS stylesheets, JavaScript files and image files
symfony/browser-kit                 7.4.0  Simulates the behavior of a web browser, allowing you to make requests, click on links and submit forms programmatically
symfony/cache                       7.4.1  Provides extended PSR-6, PSR-16 (and tags) implementations
symfony/cache-contracts             3.6.0  Generic abstractions related to caching
symfony/clock                       7.4.0  Decouples applications from the system clock
symfony/config                      7.4.1  Helps you find, load, combine, autofill and validate configuration values of any kind
symfony/console                     7.4.1  Eases the creation of beautiful and testable command line interfaces
symfony/css-selector                7.4.0  Converts CSS selectors to XPath expressions
symfony/debug-bundle                7.4.0  Provides a tight integration of the Symfony VarDumper component and the ServerLogCommand from MonologBridge into the Symfony full-stack framework
symfony/dependency-injection        7.4.2  Allows you to standardize and centralize the way objects are constructed in your application
symfony/deprecation-contracts       3.6.0  A generic function and convention to trigger deprecation notices
symfony/doctrine-bridge             7.4.1  Provides integration for Doctrine with various Symfony components
symfony/dom-crawler                 7.4.1  Eases DOM navigation for HTML and XML documents
symfony/dotenv                      7.4.0  Registers environment variables from a .env file
symfony/error-handler               7.4.0  Provides tools to manage errors and ease debugging PHP code
symfony/event-dispatcher            7.4.0  Provides tools that allow your application components to communicate with each other by dispatching events and listening to them
symfony/event-dispatcher-contracts  3.6.0  Generic abstractions related to dispatching event
symfony/expression-language         7.4.0  Provides an engine that can compile and evaluate expressions
symfony/filesystem                  7.4.0  Provides basic utilities for the filesystem
symfony/finder                      7.4.0  Finds files and directories via an intuitive fluent interface
symfony/flex                        2.10.0 Composer plugin for Symfony
symfony/form                        7.4.1  Allows to easily create, process and reuse HTML forms
symfony/framework-bundle            7.4.1  Provides a tight integration between Symfony components and the Symfony full-stack framework
symfony/http-client                 7.4.1  Provides powerful methods to fetch HTTP resources synchronously or asynchronously
symfony/http-client-contracts       3.6.0  Generic abstractions related to HTTP clients
symfony/http-foundation             7.4.1  Defines an object-oriented layer for the HTTP specification
symfony/http-kernel                 7.4.2  Provides a structured process for converting a Request into a Response
symfony/intl                        7.4.0  Provides access to the localization data of the ICU library
symfony/mailer                      7.4.0  Helps sending emails
symfony/maker-bundle                1.65.1 Symfony Maker helps you create empty commands, controllers, form classes, tests and more so you can forget about writing boilerplate code.
symfony/mime                        7.4.0  Allows manipulating MIME messages
symfony/monolog-bridge              7.4.0  Provides integration for Monolog with various Symfony components
symfony/monolog-bundle              3.11.1 Symfony MonologBundle
symfony/notifier                    7.4.0  Sends notifications via one or more channels (email, SMS, ...)
symfony/options-resolver            7.4.0  Provides an improved replacement for the array_replace PHP function
symfony/password-hasher             7.4.0  Provides password hashing utilities
symfony/phpunit-bridge              6.4.26 Provides utilities for PHPUnit, especially user deprecation notices management
symfony/polyfill-intl-grapheme      1.33.0 Symfony polyfill for intl's grapheme_* functions
symfony/polyfill-intl-icu           1.33.0 Symfony polyfill for intl's ICU-related data and classes
symfony/polyfill-intl-idn           1.33.0 Symfony polyfill for intl's idn_to_ascii and idn_to_utf8 functions
symfony/polyfill-intl-normalizer    1.33.0 Symfony polyfill for intl's Normalizer class and related functions
symfony/polyfill-mbstring           1.33.0 Symfony polyfill for the Mbstring extension
symfony/polyfill-php83              1.33.0 Symfony polyfill backporting some PHP 8.3+ features to lower PHP versions
symfony/polyfill-php84              1.33.0 Symfony polyfill backporting some PHP 8.4+ features to lower PHP versions
symfony/polyfill-php85              1.33.0 Symfony polyfill backporting some PHP 8.5+ features to lower PHP versions
symfony/process                     7.4.0  Executes commands in sub-processes
symfony/property-access             7.4.0  Provides functions to read and write from/to an object or array using a simple string notation
symfony/property-info               7.4.1  Extracts information about PHP class' properties using metadata of popular sources
symfony/routing                     7.4.0  Maps an HTTP request to a set of configuration variables
symfony/runtime                     7.4.1  Enables decoupling PHP applications from global state
symfony/security-bundle             7.4.0  Provides a tight integration of the Security component into the Symfony full-stack framework
symfony/security-core               7.4.0  Symfony Security Component - Core Library
symfony/security-csrf               7.4.0  Symfony Security Component - CSRF Library
symfony/security-http               7.4.1  Symfony Security Component - HTTP Integration
symfony/serializer                  7.4.2  Handles serializing and deserializing data structures, including object graphs, into array structures or other formats like XML and JSON.
symfony/service-contracts           3.6.1  Generic abstractions related to writing services
symfony/stimulus-bundle             2.31.0 Integration with your Symfony app & Stimulus!
symfony/stopwatch                   7.4.0  Provides a way to profile code
symfony/string                      7.4.0  Provides an object-oriented API to strings and deals with bytes, UTF-8 code points and grapheme clusters in a unified way
symfony/translation                 7.4.0  Provides tools to internationalize your application
symfony/translation-contracts       3.6.1  Generic abstractions related to translation
symfony/twig-bridge                 7.4.1  Provides integration for Twig with various Symfony components
symfony/twig-bundle                 7.4.0  Provides a tight integration of Twig into the Symfony full-stack framework
symfony/type-info                   7.4.1  Extracts PHP types information.
symfony/ux-live-component           2.31.0 Live components for Symfony
symfony/ux-turbo                    2.31.0 Hotwire Turbo integration for Symfony
symfony/ux-twig-component           2.31.0 Twig components for Symfony
symfony/ux-vue                      2.31.0 Integration of Vue.js in Symfony
symfony/validator                   7.4.2  Provides tools to validate values
symfony/var-dumper                  7.4.0  Provides mechanisms for walking through any arbitrary PHP variable
symfony/var-exporter                7.4.0  Allows exporting any serializable PHP data structure to plain PHP code
symfony/web-link                    7.4.0  Manages links between resources
symfony/web-profiler-bundle         7.4.0  Provides a development tool that gives detailed information about the execution of any request
symfony/webpack-encore-bundle       2.4.0  Integration of your Symfony app with Webpack Encore
symfony/yaml                        7.4.1  Loads and dumps YAML files
theseer/tokenizer                   2.0.1  A small library for converting tokenized PHP source code into XML and potentially other formats
twig/extra-bundle                   3.22.2 A Symfony bundle for extra Twig extensions
twig/twig                           3.22.2 Twig, the flexible, fast, and secure template language for PHP
webmozart/assert                    1.12.1 Assertions to validate method input/output with nice error messages.

PHPUnit 12.5.4 by Sebastian Bergmann and contributors.

Checking whether PHP is configured according to https://docs.phpunit.de/en/12.5/installation.html#configuring-php-for-development

display_errors = On             ... not ok ()
display_startup_errors = On     ... not ok ()
error_reporting = -1            ... not ok (22527)
xdebug.show_exception_trace = 0 ... ok
zend.assertions = 1             ... not ok (-1)
assert.exception = 1            ... ok
memory_limit = -1               ... ok