InvalidDocblock: Invalid array key type type-alias(...)

[luukvhoudt]

When importing a type and using it as the array key in another type, then I get the following error:

InvalidDocblock - XYZ.php:XYZ:XYZ - array<ValueOfGreetings, string> is not a valid type (Invalid array key type type-alias(Greetings::ValueOfGreetings) in XYZ.php:XYZ) (see https://psalm.dev/008)

I didn't manage to reproduce it in the playground, probably because the psalm version differs with the one on my machine. I'm using version 5.18.0. In any case this is the reproduction I wrote at the playground:
https://psalm.dev/r/e02932aa33

[psalm-github-bot]

I found these snippets:

https://psalm.dev/r/e02932aa33

<?php

/**
 * @psalm-type ValueOfGreetings = Greetings::*
 */
class Greetings {
    public const HI = 'hi';
    public const HELLO = 'hello';
}

/**
 * @psalm-import-type ValueOfGreetings from Greetings
 */
class Greetor {
    /**
     * @return array<ValueOfGreetings, string>
     */
    public function getAll() {
        return [
            Greetings::HI => "mom",
            Greetings::HELLO => "world",
        ];
    }
}

Psalm output (using commit a75d26a):

No issues!