UndefinedClass when aliasing imports about psalm HOT 6 CLOSED

I found these snippets:

<?php

use Foo\Exception as FooException;

class Connection
{
    public function __construct()
    {
        throw new FooException("foo");
    }
}

Psalm output (using commit ef3b018):

ERROR: UndefinedClass - 9:19 - Class, interface or enum named Foo\Exception does not exist

from psalm.

Does Foo\Exception actually exist?

from psalm.

In case I faced, it's about class from php-extention, ref symfony/symfony#53244 (comment)

from psalm.

So the error you get on psalm.dev is valid. Now let me put it another way - does Symfony CI have this extension installed?

from psalm.

Unfortunately I'm not aware of Symfony CI specifics

from psalm.

So let's assume it's not. As such, there's no problem with Psalm: it reported what it was designed to report - UndefinedClass.

from psalm.