I tried upgrading from Laravel6 to Laravel8. I edited Laravel8 in composer.json and ran composer update. I feel like it's going well, but I want to see what version dependency errors come up.

Here is the package status of Laravel6 before the change.

    "require": {
        "php": "^7.2.5|^8.0",
        "diglactic/laravel-breadcrumbs": "^6.1",
        "fideloper/proxy": "^4.4",
        "laravel/framework": "^6.20",
        "laravel/tinker": "^2.5",
        "league/flysystem-aws-s3-v3": "~1.0",
        "weidner/goutte": "^1.6"
    },
      "require-dev": {
        "facade/ignition": "^1.16.4",
        "fakerphp/faker": "^1.9.1",
        "laravel/ui": "^1.0",
        "mockery/mockery": "^1.0",
        "nunomaduro/collision": "^3.0",
        "phpunit/phpunit": "^8.5.8|^9.3.3"
    },

Conclusion (After modification)

composer.json

    "require": {
        "php": "^7.2.5|^8.0",
        "diglactic/laravel-breadcrumbs": "^6.1",
        "fideloper/proxy": "^4.4",
        "laravel/framework": "^8.0",
        "laravel/tinker": "^2.5",
        "league/flysystem-aws-s3-v3": "~1.0",
        "weidner/goutte": "^1.6"
    },
    "require-dev": {
        "facade/ignition": "^2.3.6",
        "fakerphp/faker": "^1.9.1",
        "laravel/ui": "^3.0",
        "mockery/mockery": "^1.0",
        "nunomaduro/collision": "^5.0",
        "phpunit/phpunit": "^8.5.8|^9.3.3"
    },

Further modifications are required after this.

Modify app/Exceptions/Handler.php

<?php

namespace App\Exceptions;

use Exception;
use Illuminate\Foundation\Exceptions\Handler as ExceptionHandler;

class Handler extends ExceptionHandler
{
    // Content remains the same from Laravel 6 to Laravel 8
}

Upgrade Steps

Change the Laravel version specification in composer.json

"laravel/framework": "^8.0",

Command

composer update

Version error occurs

  Problem 1
    - Conclusion: don't install laravel/framework v8.0.0 (conflict analysis result)
    ~~~~~~~~~~~~~~~
       - laravel/ui[v1.0.0, ..., 1.x-dev] require illuminate/support ~5.8|^6.0 -> satisfiable by illuminate/support[v5.8.0, ..., 5.8.x-dev, v6.0.0, ..., 6.x-dev].
    - Only one of these can be installed: illuminate/support[v5.0.0, ..., 5.8.x-dev, v6.0.0, ..., 6.x-dev, v7.0.0, ..., 7.x-dev, v8.0.0, ..., 8.x-dev], laravel/framework[v8.0.0, ..., 8.x-dev]. 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, ..., 8.x-dev].
    - Root composer.json requires laravel/ui ^1.0 -> satisfiable by laravel/ui[v1.0.0, ..., 1.x-dev].

Modify laravel/ui to version 3

Edit composer.json

  "laravel/ui": "^3.0",

Command

composer update

Version error with symfony

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

  Problem 1
    - Root composer.json requires facade/ignition ^1.16.4 -> satisfiable by facade/ignition[1.16.4, ..., v1.x-dev].
    - You can only install one version of a package, so only one of these can be installed: symfony/console[v2.3.10, ..., 2.8.x-dev, v3.0.0-BETA1, ..., 3.4.x-dev, v4.0.0-BETA1, ..., 4.4.x-dev, v5.0.0-BETA1, ..., 5.4.x-dev, 6.0.x-dev].
    - Conclusion: install symfony/console v5.1.0 (conflict analysis result)

Change as follows

    "require-dev": {
        "facade/ignition": "^2.3.6",
        "nunomaduro/collision": "^5.0",

The upgrade itself went smoothly.

However, errors occurred so I will address them in the next section.

File Modifications

Error Message

> Illuminate\Foundation\ComposerScripts::postAutoloadDump
> @php artisan package:discover --ansi
Script @php artisan package:discover --ansi handling the post-autoload-dump event returned with error code 255

After the upgrade, errors occur with php artisan commands like the above.

Modification in app/Exceptions/Handler.php

Errors seem to occur because this file has different contents between Laravel 6 and 8.

Modify the content completely to adhere to Laravel 8 specifications

<?php

namespace App\Exceptions;

use Exception;
use Illuminate\Foundation\Exceptions\Handler as ExceptionHandler;

class Handler extends ExceptionHandler
{
    // Content remains the same from Laravel 6 to Laravel 8
}

Apply the changes and run

composer update

php artisan -v
Laravel Framework 8.60.0

Successfully upgraded to Laravel 8!

⇨How to Implement Authentication in Laravel8 with Jetstream

Summary

That's all.

There are probably many similar articles out there, but I hope this was helpful.

If you have any feedback or opinions, please feel free to contact me via Twitter DM!

Thank you and goodbye!