DeprecationErrorHandler::shutdown from Symfony\Bridge\PhpUnit

[rhengles]

When just created a empty, brand new symfony project from latest versions, and trying to add tests like in the docs:
https://symfony.com/doc/current/testing.html

Before creating your first test, install symfony/test-pack, which installs some other packages needed for testing (such as phpunit/phpunit):

composer require --dev symfony/test-pack

After the library is installed, try running PHPUnit:

php bin/phpunit

This shows the following messages in the terminal:

  1x: Method "Iterator::current()" might add "mixed" as a native return type declaration in the future. Do the same in implementation "Swoole\ArrayObject" now to avoid errors or add an explicit @return annotation to suppress this message.
    1x in DeprecationErrorHandler::shutdown from Symfony\Bridge\PhpUnit

  1x: Method "Iterator::key()" might add "mixed" as a native return type declaration in the future. Do the same in implementation "Swoole\ArrayObject" now to avoid errors or add an explicit @return annotation to suppress this message.
    1x in DeprecationErrorHandler::shutdown from Symfony\Bridge\PhpUnit

  1x: Method "Iterator::rewind()" might add "void" as a native return type declaration in the future. Do the same in implementation "Swoole\ArrayObject" now to avoid errors or add an explicit @return annotation to suppress this message.
    1x in DeprecationErrorHandler::shutdown from Symfony\Bridge\PhpUnit

  1x: Method "Iterator::next()" might add "void" as a native return type declaration in the future. Do the same in implementation "Swoole\ArrayObject" now to avoid errors or add an explicit @return annotation to suppress this message.
    1x in DeprecationErrorHandler::shutdown from Symfony\Bridge\PhpUnit

  1x: Method "ArrayAccess::offsetGet()" might add "mixed" as a native return type declaration in the future. Do the same in implementation "Swoole\ArrayObject" now to avoid errors or add an explicit @return annotation to suppress this message.
    1x in DeprecationErrorHandler::shutdown from Symfony\Bridge\PhpUnit

  1x: Method "ArrayAccess::offsetExists()" might add "bool" as a native return type declaration in the future. Do the same in implementation "Swoole\ArrayObject" now to avoid errors or add an explicit @return annotation to suppress this message.
    1x in DeprecationErrorHandler::shutdown from Symfony\Bridge\PhpUnit