composer updateしたらcomposer dump-autoloadができなくなった。

#症状
laravel8でパッケージを削除してcomposer updateをしたらartisanが開けないよと言われた。

# composer dump-autoload
Generating optimized autoload files
> Illuminate\Foundation\ComposerScripts::postAutoloadDump
> @php artisan package:discover --ansi
Could not open input file: artisan
Script @php artisan package:discover --ansi handling the post-autoload-dump event returned with error code 1

artisanといわれているのでコマンドを叩いてみる

#　php artisan route:list
Could not open input file: artisan

artisanファイルがないか確認してみる

# ls
app  bootstrap	composer.json  composer.lock  config  database	node_modules  package.json  package-lock.json  phpunit.xml  public  README.md  resources  routes  server.php  storage  tests  vendor  webpack.mix.js

なぜかなくなっている。

#解決
なくなっているので作成する
下記のlaravel公式リポジトリから
https://github.com/laravel/laravel/blob/8.x/artisan

artisan

#!/usr/bin/env php
<?php

define('LARAVEL_START', microtime(true));

/*
|--------------------------------------------------------------------------
| Register The Auto Loader
|--------------------------------------------------------------------------
|
| Composer provides a convenient, automatically generated class loader
| for our application. We just need to utilize it! We'll require it
| into the script here so that we do not have to worry about the
| loading of any of our classes manually. It's great to relax.
|
*/

require __DIR__.'/vendor/autoload.php';

$app = require_once __DIR__.'/bootstrap/app.php';

/*
|--------------------------------------------------------------------------
| Run The Artisan Application
|--------------------------------------------------------------------------
|
| When we run the console application, the current CLI command will be
| executed in this console and the response sent back to a terminal
| or another output device for the developers. Here goes nothing!
|
*/

$kernel = $app->make(Illuminate\Contracts\Console\Kernel::class);

$status = $kernel->handle(
    $input = new Symfony\Component\Console\Input\ArgvInput,
    new Symfony\Component\Console\Output\ConsoleOutput
);

/*
|--------------------------------------------------------------------------
| Shutdown The Application
|--------------------------------------------------------------------------
|
| Once Artisan has finished running, we will fire off the shutdown events
| so that any final work may be done by the application before we shut
| down the process. This is the last thing to happen to the request.
|
*/

$kernel->terminate($input, $status);

exit($status);

なおった。。