Laravel PackageManifest.php line 131: Undefined index: name

I updated the composer with this command:
```
composer self-update
```
It was updated to version 2.0.4. Then when I tried to launch my Laravel project using:
```
php artisan serve
```
I got this error:
```
In PackageManifest.php line 131:

Undefined index: name
```
I tried getting back to the old version of the composer with this:
```
composer self-update --rollback
```
The composer was downgraded to version 1.9.3, but it didn't help with the error.
Then I used this command to update the composer again:
```
composer self-update --stable
```
And still got the same error.

This is the line 131 of the PackageManifest.php file:
```
return [$this->format($package['name']) => $package['extra']['laravel'] ?? []];
```

First, you should check again version after using `composer self-update`. Then, you try `composer update`. Finally, you run `php artisan serve`.

add code in Illuminate\Foundation\PackageManifest.php about to line 129:

...
$ignoreAll = in_array('*', $ignore = $this->packagesToIgnore());
// ------------------:::::::::FIX::::::::::------------
if (isset($packages['packages'])){
$packages = $packages['packages'];
}
// ---------------------------ENDFIX-------------------
$this->write(collect($packages)->mapWithKeys(function ($package) {
...

This was actually fixed in Laravel already, so please make sure you update Laravel to at least 6.18.7+ or 7.6.0+ or 8.0+

FYI, if you remove composer local file, it will update all your dependencies, so it's not a good idea.

By running the command `composer update laravel/framework` should hopefully fix the issue and not cause any other problems. If you can not update Laravel then you better off downgrade to Composer 1 using `composer self-update --1`.

If you are using `illuminate/foundation` instead of `laravel/framework`, then make sure you `composer update illuminate/foundation` instead.

Option 1:

Open
vendor/laravel/framework/src/Illuminate/Foundation/PackageManifest.php

then search code :

$packages = json_decode($this->files->get($path), true);

insert

$packages = $installed['packages'] ?? $installed;

Option 2 :

run command

composer update

this helped me :

downgrade to Composer 1 using

composer self-update --1

The issue is one of the Laravel default vendor packages has a small bug.

The solution to fix this is the following:

rm -rf composer.lock
rm -rf vendor
composer install

This will update the composer packages to the latest versions for your current version of laravel and this should resolve the issue.