Performing update with Composer ... error: An error occurred

Question

I am getting this error when upgrading craft CMS, could anyone please assist.

<warning>Package "craftcms/vue-asset" listed for update is not installed. Ignoring.</warning>
<warning>Package "yiisoft/yii2-shell" listed for update is not installed. Ignoring.</warning>
Loading composer repositories with package information
Updating dependencies
Your requirements could not be resolved to an installable set of packages.
Problem 1
    - Conclusion: don't install symfony/yaml v5.4.3
    - Conclusion: don't install symfony/yaml v5.4.2
    - Conclusion: don't install symfony/yaml v5.4.0
    - Conclusion: don't install symfony/yaml v5.3.14
    - Conclusion: don't install symfony/yaml v5.3.13
    - Conclusion: don't install symfony/yaml v5.3.11
    - Conclusion: don't install symfony/yaml v5.3.6
    - Conclusion: don't install symfony/yaml v5.3.4
    - Conclusion: remove laravel/homestead v7.20.0
    - Conclusion: don't install symfony/yaml v4.4.37
    - Conclusion: don't install symfony/yaml v5.3.3
    - Conclusion: don't install symfony/yaml v4.4.36
    - Conclusion: don't install symfony/yaml v5.3.2
    - Conclusion: don't install symfony/yaml v4.4.34
    - Conclusion: don't install symfony/yaml v5.3.0
    - Conclusion: don't install symfony/yaml v4.4.29
    - Conclusion: don't install symfony/yaml v5.2.14
    - Conclusion: don't install symfony/yaml v4.4.27

composer.json:

{
  "require": {
    "craftcms/cms": "3.5.8",
    "vlucas/phpdotenv": "^2.4.0",
    "craftcms/aws-s3": "1.2.11",
    "verbb/field-manager": "2.2.0",
    "craftcms/contact-form": "2.2.7",
    "craftcms/contact-form-honeypot": "1.0.2",
    "nystudio107/craft-cookies": "1.1.12",
    "matt-west/craft-recaptcha": "1.5.0",
    "fruitstudios/linkit": "1.1.11",
    "laravel/homestead": "^7.20",
    "craftcms/redactor": "2.7.4"
  },
  "autoload": {
    "psr-4": {
      "modules\\": "modules/"
    }
  },
  "config": {
    "optimize-autoloader": true,
    "platform": {
      "php": "7.0"
    }
  },
  "scripts": {
    "post-root-package-install": [
      "@php -r \"file_exists('.env') || copy('.env.example', '.env');\""
    ]
  }
}

Full error:

Skipping database backup.
Performing update with Composer ... error: An error occurred
Output:
<warning>Package "craftcms/vue-asset" listed for update is not installed. Ignoring.</warning>
<warning>Package "yiisoft/yii2-shell" listed for update is not installed. Ignoring.</warning>
Loading composer repositories with package information
Updating dependencies
Your requirements could not be resolved to an installable set of packages.
Problem 1
    - Conclusion: don't install symfony/yaml v5.4.3
    - Conclusion: don't install symfony/yaml v5.4.2
    - Conclusion: don't install symfony/yaml v5.4.0
    - Conclusion: don't install symfony/yaml v5.3.14
    - Conclusion: don't install symfony/yaml v5.3.13
    - Conclusion: don't install symfony/yaml v5.3.11
    - Conclusion: don't install symfony/yaml v5.3.6
    - Conclusion: don't install symfony/yaml v5.3.4
    - Conclusion: remove laravel/homestead v7.20.0
    - Conclusion: don't install symfony/yaml v4.4.37
    - Conclusion: don't install symfony/yaml v5.3.3
    - Conclusion: don't install symfony/yaml v4.4.36
    - Conclusion: don't install symfony/yaml v5.3.2
    - Conclusion: don't install symfony/yaml v4.4.34
    - Conclusion: don't install symfony/yaml v5.3.0
    - Conclusion: don't install symfony/yaml v4.4.29
    - Conclusion: don't install symfony/yaml v5.2.14
    - Conclusion: don't install symfony/yaml v4.4.27
    - Conclusion: don't install symfony/yaml v5.2.12
    - Conclusion: don't install symfony/yaml v4.4.26
    - Conclusion: don't install symfony/yaml v5.2.11
    - Conclusion: don't install symfony/yaml v4.4.25
    - Conclusion: don't install symfony/yaml v5.2.10
    - Conclusion: don't install symfony/yaml v4.4.24
    - Conclusion: don't install symfony/yaml v5.2.9
    - Conclusion: don't install symfony/yaml v4.4.22
    - Conclusion: don't install symfony/yaml v5.2.7
    - Conclusion: don't install symfony/yaml v4.4.21
    - Conclusion: don't install symfony/yaml v5.2.5
    - Conclusion: don't install symfony/yaml v4.4.20
    - Conclusion: don't install symfony/yaml v5.2.4
    - Conclusion: don't install symfony/yaml v4.4.19
    - Conclusion: don't install symfony/yaml v5.2.3
    - Conclusion: don't install symfony/yaml v4.4.18
    - Installation request for craftcms/cms 3.7.27.2 -> satisfiable by craftcms/cms[3.7.27.2].
    - Installation request for laravel/homestead ^7.20 -> satisfiable by laravel/homestead[v7.20.0].
    - laravel/homestead v7.20.0 requires symfony/yaml ~3.3|~4.0 -> satisfiable by symfony/yaml[v3.3.6, v4.4.37, v4.4.36, v4.4.34, v4.4.29, v4.4.27, v4.4.26, v4.4.25, v4.4.24, v4.4.22, v4.4.21, v4.4.20, v4.4.19, v4.4.18, v4.4.17, v4.4.16, v4.4.15, v4.4.14, v4.4.13, v4.4.12, v4.4.11, v4.4.10, v4.4.9, v4.4.8, v4.4.7, v4.4.6, v4.4.5, v4.4.4, v4.4.3, v4.4.2, v4.4.1, v4.4.0, v4.3.11, v4.3.10, v4.3.9, v4.3.8, v4.3.7, v4.3.6, v4.3.5, v4.3.4, v4.3.3, v4.3.2, v4.3.1, v4.3.0, v4.2.12, v4.2.11, v4.2.10, v4.2.9, v4.2.8, v4.2.7, v4.2.6, v4.2.5, v4.2.4, v4.2.3, v4.2.2, v4.2.1, v4.2.0, v4.1.12, v4.1.11, v4.1.10, v4.1.9, v4.1.8, v4.1.7, v4.1.6, v4.1.5, v4.1.4, v4.1.3, v4.1.2, v4.1.1, v4.1.0, v4.0.15, v4.0.14, v4.0.13, v4.0.12, v4.0.11, v4.0.10, v4.0.9, v4.0.8, v4.0.7, v4.0.6, v4.0.5, v4.0.4, v4.0.3, v4.0.2, v4.0.1, v4.0.0, v3.4.47, v3.4.46, v3.4.45, v3.4.44, v3.4.43, v3.4.42, v3.4.41, v3.4.40, v3.4.39, v3.4.38, v3.4.37, v3.4.36, v3.4.35, v3.4.34, v3.4.33, v3.4.32, v3.4.31, v3.4.30, v3.4.29, v3.4.28, v3.4.27, v3.4.26, v3.4.25, v3.4.24, v3.4.23, v3.4.22, v3.4.21, v3.4.20, v3.4.19, v3.4.18, v3.4.17, v3.4.16, v3.4.15, v3.4.14, v3.4.13, v3.4.12, v3.4.11, v3.4.10, v3.4.9, v3.4.8, v3.4.7, v3.4.6, v3.4.5, v3.4.4, v3.4.3, v3.4.2, v3.4.1, v3.4.0, v3.3.18, v3.3.17, v3.3.16, v3.3.15, v3.3.14, v3.3.13, v3.3.12, v3.3.11, v3.3.10, v3.3.9, v3.3.8, v3.3.7, v3.3.5, v3.3.4, v3.3.3, v3.3.2, v3.3.1, v3.3.0].
    - Can only install one of: symfony/yaml[v4.4.17, v5.2.1].
    - Can only install one of: symfony/yaml[v4.4.16, v5.2.1].
    - Can only install one of: symfony/yaml[v4.4.15, v5.2.1].
    - Can only install one of: symfony/yaml[v4.4.14, v5.2.1].
    - Can only install one of: symfony/yaml[v4.4.13, v5.2.1].
    - Can only install one of: symfony/yaml[v4.4.12, v5.2.1].
    - Can only install one of: symfony/yaml[v4.4.11, v5.2.1].
    - Can only install one of: symfony/yaml[v4.4.10, v5.2.1].
    - Can only install one of: symfony/yaml[v4.4.9, v5.2.1].
    - Can only install one of: symfony/yaml[v4.4.8, v5.2.1].
    - Can only install one of: symfony/yaml[v4.4.7, v5.2.1].
    - Can only install one of: symfony/yaml[v4.4.6, v5.2.1].
    - Can only install one of: symfony/yaml[v4.4.5, v5.2.1].
    - Can only install one of: symfony/yaml[v4.4.4, v5.2.1].
    - Can only install one of: symfony/yaml[v4.4.3, v5.2.1].
    - Can only install one of: symfony/yaml[v4.4.2, v5.2.1].
    - Can only install one of: symfony/yaml[v4.4.1, v5.2.1].
    - Can only install one of: symfony/yaml[v4.4.0, v5.2.1].
    - Can only install one of: symfony/yaml[v4.3.11, v5.2.1].
    - Can only install one of: symfony/yaml[v4.3.10, v5.2.1].
    - Can only install one of: symfony/yaml[v4.3.9, v5.2.1].
    - Can only install one of: symfony/yaml[v4.3.8, v5.2.1].
    - Can only install one of: symfony/yaml[v4.3.7, v5.2.1].
    - Can only install one of: symfony/yaml[v4.3.6, v5.2.1].
    - Can only install one of: symfony/yaml[v4.3.5, v5.2.1].
    - Can only install one of: symfony/yaml[v4.3.4, v5.2.1].
    - Can only install one of: symfony/yaml[v4.3.3, v5.2.1].
    - Can only install one of: symfony/yaml[v4.3.2, v5.2.1].
    - Can only install one of: symfony/yaml[v4.3.1, v5.2.1].
    - Can only install one of: symfony/yaml[v4.3.0, v5.2.1].
    - Can only install one of: symfony/yaml[v4.2.12, v5.2.1].
    - Can only install one of: symfony/yaml[v4.2.11, v5.2.1].
    - Can only install one of: symfony/yaml[v4.2.10, v5.2.1].
    - Can only install one of: symfony/yaml[v4.2.9, v5.2.1].
    - Can only install one of: symfony/yaml[v4.2.8, v5.2.1].
    - Can only install one of: symfony/yaml[v4.2.7, v5.2.1].
    - Can only install one of: symfony/yaml[v4.2.6, v5.2.1].
    - Can only install one of: symfony/yaml[v4.2.5, v5.2.1].
    - Can only install one of: symfony/yaml[v4.2.4, v5.2.1].
    - Can only install one of: symfony/yaml[v4.2.3, v5.2.1].
    - Can only install one of: symfony/yaml[v4.2.2, v5.2.1].
    - Can only install one of: symfony/yaml[v4.2.1, v5.2.1].
    - Can only install one of: symfony/yaml[v4.2.0, v5.2.1].
    - Can only install one of: symfony/yaml[v4.1.12, v5.2.1].
    - Can only install one of: symfony/yaml[v4.1.11, v5.2.1].
    - Can only install one of: symfony/yaml[v4.1.10, v5.2.1].
    - Can only install one of: symfony/yaml[v4.1.9, v5.2.1].
    - Can only install one of: symfony/yaml[v4.1.8, v5.2.1].
    - Can only install one of: symfony/yaml[v4.1.7, v5.2.1].
    - Can only install one of: symfony/yaml[v4.1.6, v5.2.1].
    - Can only install one of: symfony/yaml[v4.1.5, v5.2.1].
    - Can only install one of: symfony/yaml[v4.1.4, v5.2.1].
    - Can only install one of: symfony/yaml[v4.1.3, v5.2.1].
    - Can only install one of: symfony/yaml[v4.1.2, v5.2.1].
    - Can only install one of: symfony/yaml[v4.1.1, v5.2.1].
    - Can only install one of: symfony/yaml[v4.1.0, v5.2.1].
    - Can only install one of: symfony/yaml[v4.0.15, v5.2.1].
    - Can only install one of: symfony/yaml[v4.0.14, v5.2.1].
    - Can only install one of: symfony/yaml[v4.0.13, v5.2.1].
    - Can only install one of: symfony/yaml[v4.0.12, v5.2.1].
    - Can only install one of: symfony/yaml[v4.0.11, v5.2.1].
    - Can only install one of: symfony/yaml[v4.0.10, v5.2.1].
    - Can only install one of: symfony/yaml[v4.0.9, v5.2.1].
    - Can only install one of: symfony/yaml[v4.0.8, v5.2.1].
    - Can only install one of: symfony/yaml[v4.0.7, v5.2.1].
    - Can only install one of: symfony/yaml[v4.0.6, v5.2.1].
    - Can only install one of: symfony/yaml[v4.0.5, v5.2.1].
    - Can only install one of: symfony/yaml[v4.0.4, v5.2.1].
    - Can only install one of: symfony/yaml[v4.0.3, v5.2.1].
    - Can only install one of: symfony/yaml[v4.0.2, v5.2.1].
    - Can only install one of: symfony/yaml[v4.0.1, v5.2.1].
    - Can only install one of: symfony/yaml[v4.0.0, v5.2.1].
    - Can only install one of: symfony/yaml[v3.4.47, v5.2.1].
    - Can only install one of: symfony/yaml[v3.4.46, v5.2.1].
    - Can only install one of: symfony/yaml[v3.4.45, v5.2.1].
    - Can only install one of: symfony/yaml[v3.4.44, v5.2.1].
    - Can only install one of: symfony/yaml[v3.4.43, v5.2.1].
    - Can only install one of: symfony/yaml[v3.4.42, v5.2.1].
    - Can only install one of: symfony/yaml[v3.4.41, v5.2.1].
    - Can only install one of: symfony/yaml[v3.4.40, v5.2.1].
    - Can only install one of: symfony/yaml[v3.4.39, v5.2.1].
    - Can only install one of: symfony/yaml[v3.4.38, v5.2.1].
    - Can only install one of: symfony/yaml[v3.4.37, v5.2.1].
    - Can only install one of: symfony/yaml[v3.4.36, v5.2.1].
    - Can only install one of: symfony/yaml[v3.4.35, v5.2.1].
    - Can only install one of: symfony/yaml[v3.4.34, v5.2.1].
    - Can only install one of: symfony/yaml[v3.4.33, v5.2.1].
    - Can only install one of: symfony/yaml[v3.4.32, v5.2.1].
    - Can only install one of: symfony/yaml[v3.4.31, v5.2.1].
    - Can only install one of: symfony/yaml[v3.4.30, v5.2.1].
    - Can only install one of: symfony/yaml[v3.4.29, v5.2.1].
    - Can only install one of: symfony/yaml[v3.4.28, v5.2.1].
    - Can only install one of: symfony/yaml[v3.4.27, v5.2.1].
    - Can only install one of: symfony/yaml[v3.4.26, v5.2.1].
    - Can only install one of: symfony/yaml[v3.4.25, v5.2.1].
    - Can only install one of: symfony/yaml[v3.4.24, v5.2.1].
    - Can only install one of: symfony/yaml[v3.4.23, v5.2.1].
    - Can only install one of: symfony/yaml[v3.4.22, v5.2.1].
    - Can only install one of: symfony/yaml[v3.4.21, v5.2.1].
    - Can only install one of: symfony/yaml[v3.4.20, v5.2.1].
    - Can only install one of: symfony/yaml[v3.4.19, v5.2.1].
    - Can only install one of: symfony/yaml[v3.4.18, v5.2.1].
    - Can only install one of: symfony/yaml[v3.4.17, v5.2.1].
    - Can only install one of: symfony/yaml[v3.4.16, v5.2.1].
    - Can only install one of: symfony/yaml[v3.4.15, v5.2.1].
    - Can only install one of: symfony/yaml[v3.4.14, v5.2.1].
    - Can only install one of: symfony/yaml[v3.4.13, v5.2.1].
    - Can only install one of: symfony/yaml[v3.4.12, v5.2.1].
    - Can only install one of: symfony/yaml[v3.4.11, v5.2.1].
    - Can only install one of: symfony/yaml[v3.4.10, v5.2.1].
    - Can only install one of: symfony/yaml[v3.4.9, v5.2.1].
    - Can only install one of: symfony/yaml[v3.4.8, v5.2.1].
    - Can only install one of: symfony/yaml[v3.4.7, v5.2.1].
    - Can only install one of: symfony/yaml[v3.4.6, v5.2.1].
    - Can only install one of: symfony/yaml[v3.4.5, v5.2.1].
    - Can only install one of: symfony/yaml[v3.4.4, v5.2.1].
    - Can only install one of: symfony/yaml[v3.4.3, v5.2.1].
    - Can only install one of: symfony/yaml[v3.4.2, v5.2.1].
    - Can only install one of: symfony/yaml[v3.4.1, v5.2.1].
    - Can only install one of: symfony/yaml[v3.4.0, v5.2.1].
    - Can only install one of: symfony/yaml[v3.3.18, v5.2.1].
    - Can only install one of: symfony/yaml[v3.3.17, v5.2.1].
    - Can only install one of: symfony/yaml[v3.3.16, v5.2.1].
    - Can only install one of: symfony/yaml[v3.3.15, v5.2.1].
    - Can only install one of: symfony/yaml[v3.3.14, v5.2.1].
    - Can only install one of: symfony/yaml[v3.3.13, v5.2.1].
    - Can only install one of: symfony/yaml[v3.3.12, v5.2.1].
    - Can only install one of: symfony/yaml[v3.3.11, v5.2.1].
    - Can only install one of: symfony/yaml[v3.3.10, v5.2.1].
    - Can only install one of: symfony/yaml[v3.3.9, v5.2.1].
    - Can only install one of: symfony/yaml[v3.3.8, v5.2.1].
    - Can only install one of: symfony/yaml[v3.3.7, v5.2.1].
    - Can only install one of: symfony/yaml[v3.3.6, v5.2.1].
    - Can only install one of: symfony/yaml[v3.3.5, v5.2.1].
    - Can only install one of: symfony/yaml[v3.3.4, v5.2.1].
    - Can only install one of: symfony/yaml[v3.3.3, v5.2.1].
    - Can only install one of: symfony/yaml[v3.3.2, v5.2.1].
    - Can only install one of: symfony/yaml[v3.3.1, v5.2.1].
    - Can only install one of: symfony/yaml[v3.3.0, v5.2.1].
    - Can only install one of: symfony/yaml[v5.2.1, v3.3.6].
    - Can only install one of: symfony/yaml[v5.2.1, v3.3.6].
    - craftcms/cms 3.7.27.2 requires symfony/yaml ^5.2.1 -> satisfiable by symfony/yaml[v5.4.3, v5.4.2, v5.4.0, v5.3.14, v5.3.13, v5.3.11, v5.3.6, v5.3.4, v5.3.3, v5.3.2, v5.3.0, v5.2.14, v5.2.12, v5.2.11, v5.2.10, v5.2.9, v5.2.7, v5.2.5, v5.2.4, v5.2.3, v5.2.2, v5.2.1].
    - Conclusion: don't install symfony/yaml v5.2.2
<warning>Running update with --no-dev does not mean require-dev is ignored, it just means the packages will not be installed. If dev requirements are blocking the update you have to resolve those problems.</warning>

Answer 1

This error is usually caused by some outdated dependencies or some mismatch between your installed dependencies and your composer.json and composer.lock files. It could also be that the Craft updater is trying to update the specified packages for some reason, but they're not installed, so Composer is throwing a warning. For example, if you check the craftcms/vue-asset repository, you can see it's deprecated and should not be used anymore.

To fix this error, you need to figure out if this package is required by either your project itself or by another dependency (for instance, a plugin) – probably the latter. You can ask Composer for this information:

composer why craftcms/vue-asset

If the package is installed in your project itself, you can simply remove it. Of course you'll need to check if it's actually in use and if so, update this part of the codebase to use the recommended alternative instead.

composer remove craftcms/vue-asset

If the package is required by a dependency, you need to either remove or update that dependency.

---

To find out more about the errors you're getting, make sure to run the update method from a shell, not from the backend, so you can see all error messages:

php craft update all

You can also try to update through Composer directly, this will tell you what conflicts are preventing the update:

composer update --with-all-dependencies --dry-run

If this succeeds with no problems, run it again without --dry-run.

---

As a sidenote, the error you listed doesn't exist in the current Composer version any more, make sure to update to the latest version:

composer self-update

---

Update regarding version conflicts

The error messages you're receiving means there's a conflict between some dependencies. To resolve this, you need to update and/or remove dependencies until you have a set of dependencies that resolves to an installable set of dependencies.

In your concrete case, it looks like the problem is Laravel Homestead. Your composer.json requires laravel/homestead:^7.2.0, which is very outdated. This version requires symfony/yaml ~3.3|~4.0 while the version of craftcms/craft you're trying to update to requires the same package in version ^5.2.1. Satisfying both of those isn't possible, so Composer can't resolve your dependencies.

Either update or remove laravel/homestead, then try the Craft update again. If you get more errors, check which dependency is causing them and resolve the problem in the same way. Keep going until you have a set of dependencies that will update cleanly.