composer-installer

{
    "extra": {
        "spip": {
            "template": "vendor/default-template",
            "extensions": [
                "vendor1/plugin-dist-1",
                "vendor2/plugin-dist-2"
            ]
        }
    }
}

{
    "config": {
        "preferred-install": {
            "spip/*": "source"
        }
    },
    "scripts": {
        "mode-dev": [
            "Spip\\Composer\\ModeDev::activate"
        ]
    }
}

composer install
composer mode-dev