Composer dependencies not using correct PHP version

[ragulka]

I'm trying to make sure that any composer dependencies that get installed work with PHP 7.4 - for comptibility reasons. I have defined the platform (as well as php version) in both composer.json and composer-deps.json:

composer.json

{
    "autoload": {
        "psr-4": {
            "MyPlugin\\": "src/"
        }
    },
    "require": {
        "php": "^7.4 || ^8.0"
    },
    "extra": {
        "wpify-scoper": {
            "prefix": "MyDeps",
            "folder": "deps",
            "globals": [
                "wordpress",
                "woocommerce"
            ],
            "expose-global-constants": true,
            "composerjson": "composer-deps.json",
            "composerlock": "composer-deps.lock",
            "autorun": true
        }
    },
    "require-dev": {
        "wpify/scoper": "*"
    },
    "scripts": {
        "wpify-scoper": "wpify-scoper"
    },
    "config": {
        "platform": {
            "php": "7.4"
        },
        "allow-plugins": {
            "wpify/scoper": true,
            "php-http/discovery": true
        }
    }
}

composer-deps.json

{
    "config": {
        "platform": {
          "php": "7.4"
        }
    },
    "require": {
        "php": "^7.4 || ^8.0",
        "illuminate/support": "^8.83"
    }
}

However, after composer update, and trying to visit the site I get the composer platform check error:

Fatal error: Composer detected issues in your platform: Your Composer dependencies require a PHP version ">= 8.1.0". You are running 7.4.33.

I would expect that dependencies should not require PHP 8.1 if my platform is set to 7.4.

Is there a way to work around or fix this?

[ragulka]

The culprit here seems to be the fact that I was requiring wpify/scoper locally:

    "require-dev": {
        "wpify/scoper": "*"
    },

I now tried removing it and composer global require wpify/scoper and the dependencies are installed using the correct version now.

FWIW, trying to use version 3.1.3 of wpify/scoper in require-dev did not work - it would still install dependencies that required PHP 8.1, even if was actually running PHP 7.4