sh: symfony-cmd: command not found

Question

I have downgraded a Symfony 5.2 app template to use Symfony 4.4 in order to allow the use of some libraries that require an older version of Symfony. The problem is that when I do composer install, I get this error near the end of the installation:

sh: symfony-cmd: command not found

It seems that the installations are mostly successful, as my vendor folder is created and populated. But I'm worried about the error.

What does this error mean? How do I fix it?

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Edit: Here's my composer.json file:

{
    "type": "project",
    "license": "proprietary",
    "minimum-stability": "dev",
    "prefer-stable": true,
    "require": {
        "php": ">=7.4.0",
        "ext-ctype": "*",
        "ext-iconv": "*",
        "ext-json": "*",
        "composer/package-versions-deprecated": "1.11.99.1",
        "cweagans/composer-patches": "^1.7",
        "doctrine/doctrine-bundle": "^2.4",
        "doctrine/doctrine-migrations-bundle": "^3.1",
        "doctrine/orm": "^2.9",
        "phpdocumentor/reflection-docblock": "*",
        "sensio/framework-extra-bundle": "*",
        "symfony/framework-bundle": "4.4.*",
        "symfony/http-client": "*",
        "symfony/intl": "*",
        "symfony/mailer": "*",
        "symfony/mime": "*",
        "symfony/monolog-bundle": "^3.1",
        "symfony/notifier": "*",
        "symfony/process": "*",
        "symfony/property-access": "*",
        "symfony/property-info": "*",
        "symfony/proxy-manager-bridge": "*",
        "symfony/security-bundle": "*",
        "symfony/serializer": "*",
        "symfony/string": "*",
        "symfony/translation": "*",
        "symfony/twig-bundle": "*",
        "symfony/validator": "*",
        "symfony/web-link": "*",
        "symfony/yaml": "*",
        "twig/extra-bundle": "*",
        "twig/twig": "*"
    },
    "require-dev": {
        "doctrine/doctrine-fixtures-bundle": "^3.4",
        "roave/security-advisories": "dev-master",
        "symfony/browser-kit": "*",
        "symfony/css-selector": "*",
        "symfony/debug-bundle": "*",
        "symfony/maker-bundle": "*",
        "symfony/phpunit-bridge": "*",
        "symfony/stopwatch": "*",
        "symfony/var-dumper": "*",
        "symfony/web-profiler-bundle": "*",
        "vimeo/psalm": "^4.9"
    },
    "config": {
        "optimize-autoloader": true,
        "preferred-install": {
            "*": "dist"
        },
        "sort-packages": true
    },
    "autoload": {
        "psr-4": {
            "App\\": "src/"
        }
    },
    "autoload-dev": {
        "psr-4": {
            "App\\Tests\\": "tests/"
        }
    },
    "replace": {
        "symfony/polyfill-ctype": "*",
        "symfony/polyfill-iconv": "*",
        "symfony/polyfill-php72": "*"
    },
    "scripts": {
        "auto-scripts": {
            "cache:clear": "symfony-cmd",
            "assets:install %PUBLIC_DIR%": "symfony-cmd"
        },
        "post-install-cmd": [
            "@auto-scripts"
        ],
        "post-update-cmd": [
            "@auto-scripts"
        ]
    },
    "conflict": {
        "symfony/symfony": "*"
    },
    "extra": {
        "symfony": {
            "allow-contrib": false,
            "require": "5.2.*"
        },
        "patches": {
            "symfony/maker-bundle": {
                "Provide flag to force annotation in make entity command": "https://raw.githubusercontent.com/vklux/maker-bundle-force-annotation/master/maker-force-annotation-flag.patch"
            }
        }
    }
}

Answer 1

For those who have the symfony/flex package installed and are still getting the error, make sure the symfony/flex package is allowed to execute code when running composer.

This is because since Composer 2.2.0 the allow-plugins option adds a layer of security that allows you to restrict which Composer plugins can execute code at startup time.

So make sure you have the appropriate line in the allow-plugins config in your composer.json file

"config": { 
    // other config...

    "allow-plugins": {
        "symfony/flex": true
    }
},