Error with version 4.13.0 using DOMNodeList::count introduced only from PHP 7.2

[AlessandroMinoccheri]

I, I have a problem in our project with the new version 4.13.0

This is the config file used without problems since some days ago.

<?xml version="1.0"?>
<psalm
    errorLevel="3"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="https://getpsalm.org/schema/config"
    xsi:schemaLocation="https://getpsalm.org/schema/config vendor/vimeo/psalm/config.xsd"
>
    <projectFiles>
        <directory name="src" />
        <ignoreFiles>
            <directory name="vendor" />
        </ignoreFiles>
    </projectFiles>
</psalm>

I have some problems with PHP 7.1 and the error is:

Uncaught Error: Call to undefined method DOMNodeList::count() in /home/runner/work/arkitect/arkitect/vendor/vimeo/psalm/src/Psalm/Config.php:814

The problem is: The count() method (aka the Countable interface) on DOMNodeLists has been implemented since PHP 7.2.
You can see the Stack Trace here into our Github actions:

https://github.com/phparkitect/arkitect/runs/4304237741?check_suite_focus=true

[orklah]

related to https://github.com/vimeo/psalm/pull/6913/files#diff-8d07f6a86af4900069be3c80774a29e2e7e2ffaffe434c781ba95de859cf874dR814

I'd have expected Psalm to pick this up, the callmap is correct, however, DOMNodeList is flagged as implementing Countable: https://github.com/vimeo/psalm/blob/master/stubs/DOM.phpstub#L40

so count is inherited, independently from callmap

[weirdan]

Fixed in #6981