upgrade from laravel 7 to laravel 8

Question

I am trying to upgrade from laravel 7 to 8 bug i got the error

Your requirements could not be resolved to an installable set of packages.

Problem 1

- Conclusion: don't install laravel/framework v8.0.1 (conflict analysis result)
- Conclusion: don't install laravel/framework v8.0.2 (conflict analysis result)
- Conclusion: don't install laravel/framework v8.0.3 (conflict analysis result)
- Conclusion: don't install laravel/framework v8.33.0 (conflict analysis result)
- Conclusion: don't install laravel/framework v8.33.1 (conflict analysis result)
- laravel/horizon[v4.0.0, ..., v4.3.5] require illuminate/support ^7.0 -> satisfiable by illuminate/support[v7.0.0, ..., v7.30.4].
- Only one of these can be installed: illuminate/support[v5.0.0, ..., v5.8.36, v6.0.0, ..., v6.20.19, v7.0.0, ..., v7.30.4, v8.0.0, ..., v8.33.1], laravel/framework[v8.0.0, ..., v8.33.1]. laravel/framework replaces illuminate/support and thus cannot coexist with it.
- Root composer.json requires laravel/framework ^8.0 -> satisfiable by laravel/framework[v8.0.0, ..., v8.33.1].
- Root composer.json requires laravel/horizon ^4.0 -> satisfiable by laravel/horizon[v4.0.0, ..., v4.3.5].

Use the option --with-all-dependencies (-W) to allow upgrades, downgrades and removals for packages currently locked to specific versions.

my composer

 "require": {
    "php": "^7.2",
    "creativeorange/gravatar": "~1.0",
    "doctrine/dbal": "^2.5",
    "facade/ignition": "^2.3.6",
    "fideloper/proxy": "~4.0",
    "fruitcake/laravel-cors": "^2.0",
    "guzzlehttp/guzzle": "^7.0.1",
    "laravel/framework": "^8.0",
    "laravel/helpers": "^1.1",
    "laravel/horizon": "^4.0",
    "laravel/sanctum": "^2.3",
    "laravel/tinker": "^2.0",
    "laravel/ui": "^3.0",
    "predis/predis": "^1.1",
    "spatie/laravel-backup": "^6.10",
    "spatie/laravel-permission": "^3.6",
    "yajra/laravel-datatables-fractal": "^1.6",
    "yajra/laravel-datatables-oracle": "^9.0"
},
"require-dev": {
    "composer/composer": "^1.9",
    "fzaninotto/faker": "~1.4",
    "mockery/mockery": "~1.0",
    "nunomaduro/collision": "^5.0",
    "phpunit/phpunit": "^9.0"
},

what is the error , how can i fix it ?

Answer 1

You have to follow the steps provided below from scratch:

1. Backup Your composer.json:

   • Make a backup of your current composer.json file just to be safe.

2. Update composer.json:

   • Visit https://github.com/laravel-shift/laravel-8.x/blob/master/composer.json and copy the content of the composer.json file from there. Replace the content of your existing composer.json file with the copied content.

3. Update Exception Handler:

   • Similarly, go here https://github.com/laravel-shift/laravel-8.x/blob/master/app/Exceptions/Handler.php and copy the content of the Handler.php file. Then, navigate to your project's app/exceptions directory and replace the content of the existing Handler.php file with the copied content.

4. Run composer update:

   • Run the command composer update in your project's root directory.

5. Check for New Packages:

   • Take a look at your old composer.json file. if packages have been added to it, you can install them using the command composer require <package name>.

6. Update Composer Again:

   • Lastly, run the command composer update again to ensure everything is up to date.

Answer 2

I have used composer install --ignore-platform-reqs and then php artisan serve and it worked for me.

But before we got to this I have updated PHP and Laravel in composer.json to the versions I needed.

Answer 3

The error message is pretty clear:

• laravel/horizon[v4.0.0, ..., v4.3.5] require illuminate/support ^7.0 -> satisfiable by illuminate/support[v7.0.0, ..., v7.30.4].

You also need to update all other packages, like laravel/horizon. Currently, you require v4 which is not compatible with Laravel 8. Update that package to v5 which is compatible with Laravel 8.