Everything blowed up after php 8.0

Have you checked that your global composer.json file don't have the php-cs-fixer in it still?

composer global remove friendsofphp/php-cs-fixer

  LivewireTest git:(master) ✗ composer global remove friendsofphp/php-cs-fixer

Changed current directory to /Users/reniar/.composer
./composer.json has been updated
Running composer update friendsofphp/php-cs-fixer
Loading composer repositories with package information
Updating dependencies
Your requirements could not be resolved to an installable set of packages.

  Problem 1
    - phpunit/phpunit is locked to version 9.2.1 and an update of this package was not requested.
    - phpunit/phpunit 9.2.1 requires php ^7.3 -> your php version (8.0.0) does not satisfy that requirement.
  Problem 2
    - laravel/installer is locked to version v4.0.5 and an update of this package was not requested.
    - laravel/installer v4.0.5 requires php ^7.3 -> your php version (8.0.0) does not satisfy that requirement.
  Problem 3
    - illuminate/container v7.14.1 requires php ^7.2.5 -> your php version (8.0.0) does not satisfy that requirement.
    - laravel/valet v2.10.3 requires illuminate/container ~5.1 | ^6.0 | ^7.0 -> satisfiable by illuminate/container[v7.14.1].
    - laravel/valet is locked to version v2.10.3 and an update of this package was not requested.


Removal failed, reverting ./composer.json to its original content.
Removal failed, friendsofphp/php-cs-fixer is still present, it may be required by another package. See `composer why friendsofphp/php-cs-fixer`.
➜  LivewireTest git:(master) ✗ composer why friendsofphp/php-cs-fixer


  [InvalidArgumentException]
  Could not find package "friendsofphp/php-cs-fixer" in your project


depends [-r|--recursive] [-t|--tree] [--] <package> [<constraint>]

Sounds like you have some global installs there :)

Try

composer global require phpunit/phpunit -W

composer global require phpunit/phpunit -W


Changed current directory to /Users/reniar/.composer
Using version ^9.4 for phpunit/phpunit
./composer.json has been updated
Running composer update phpunit/phpunit --with-all-dependencies
Loading composer repositories with package information
Updating dependencies
Your requirements could not be resolved to an installable set of packages.

  Problem 1
    - friendsofphp/php-cs-fixer is locked to version v2.16.7 and an update of this package was not requested.
    - friendsofphp/php-cs-fixer v2.16.7 requires php ^7.1 -> your php version (8.0.0) does not satisfy that requirement.
  Problem 2
    - laravel/installer is locked to version v4.0.5 and an update of this package was not requested.
    - laravel/installer v4.0.5 requires php ^7.3 -> your php version (8.0.0) does not satisfy that requirement.
  Problem 3
    - illuminate/container v7.14.1 requires php ^7.2.5 -> your php version (8.0.0) does not satisfy that requirement.
    - laravel/valet v2.10.3 requires illuminate/container ~5.1 | ^6.0 | ^7.0 -> satisfiable by illuminate/container[v7.14.1].
    - laravel/valet is locked to version v2.10.3 and an update of this package was not requested.


Installation failed, reverting ./composer.json and ./composer.lock to their original content.

Just assuming you are running linux. Can you post the content of /home/YOURUSERNAME/.config/composer/composer.json

{
    "require": {
        "friendsofphp/php-cs-fixer": "^2.16",
        "laravel/valet": "^2.10",
        "phpunit/phpunit": "^9.2",
        "laravel/installer": "^4.0",
        "squizlabs/php_codesniffer": "*"
    }
}

on mac in

/Users/USERNAME/.composer

composer global update -W
Changed current directory to /Users/reniar/.composer
Loading composer repositories with package information
Updating dependencies
Your requirements could not be resolved to an installable set of packages.

  Problem 1
    - friendsofphp/php-cs-fixer[v2.16.0, ..., v2.16.5] require php ^5.6 || ^7.0 -> your php version (8.0.0) does not satisfy that requirement.
    - friendsofphp/php-cs-fixer v2.16.6 requires php ^7.0 -> your php version (8.0.0) does not satisfy that requirement.
    - friendsofphp/php-cs-fixer v2.16.7 requires php ^7.1 -> your php version (8.0.0) does not satisfy that requirement.
    - Root composer.json requires friendsofphp/php-cs-fixer ^2.16 -> satisfiable by friendsofphp/php-cs-fixer[v2.16.0, ..., v2.16.7].

Ah seems that cs fixer does not support php 8 yet. Either remove it from that json file, and run the command again, or downgrade to php 7.4 for now :)

https://github.com/FriendsOfPHP/PHP-CS-Fixer/blob/2.16/composer.json#L17

This is another correct answer that solved my problem everything is running flawlesly after I could now successfully run my comands

composer global update && valet install

I never used that tool php cs fixer anyways