I have an old laravel app (v6) that is still running on PHP 7.4
Laravel and PHP versions both out of support, I know! That upgrade is a task for another day.
But strange error started when running composer update.
/usr/bin/php7.2 /usr/bin/composer upgrade
During inheritance of ArrayAccess: Uncaught ErrorException: Return type of Illuminate\Support\Collection::offsetExists($key) should either be compatible with ArrayAccess::offsetExists(mixed $offset): bool,
or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in /var/www/html/core/vendor/laravel/framework/src/Illuminate/Support/Collection.php:1277
Stack trace:
#0 /var/www/html/core/vendor/laravel/framework/src/Illuminate/Support/Collection.php(11): Illuminate\Foundation\Bootstrap\HandleExceptions->handleError()
#1 /var/www/html/core/vendor/composer/ClassLoader.php(576): include('...')
#2 /var/www/html/core/vendor/composer/ClassLoader.php(427): Composer\Autoload\{closure}()
#3 /var/www/html/core/vendor/laravel/framework/src/Illuminate/Support/helpers.php(109): Composer\Autoload\ClassLoader->loadClass()
#4 /var/www/html/core/vendor/laravel/framework/src/Illuminate/Foundation/PackageManifest.php(89): collect()
#5 /var/www/html/core/vendor/laravel/framework/src/Illuminate/Foundation/PackageManifest.php(78): Illuminate\Foundation\PackageManifest->config()
#6 /var/www/html/core/vendor/laravel/framework/src/Illuminate/Foundation/Bootstrap/RegisterFacades.php(26): Illuminate\Foundation\PackageManifest->aliases()
#7 /var/www/html/core/vendor/laravel/framework/src/Illuminate/Foundation/Application.php(219): Illuminate\Foundation\Bootstrap\RegisterFacades->bootstrap()
#8 /var/www/html/core/vendor/laravel/framework/src/Illuminate/Foundation/Console/Kernel.php(320): Illuminate\Foundation\Application->bootstrapWith()
#9 /var/www/html/core/vendor/laravel/framework/src/Illuminate/Foundation/Console/Kernel.php(129): Illuminate\Foundation\Console\Kernel->bootstrap()
#10 /var/www/html/core/artisan(34): Illuminate\Foundation\Console\Kernel->handle()
#11 {main}
This error seems to be a mismatch between php version and code format, however the error doesn't make sense.
https://www.php.net/manual/en/class.returntypewillchange.php The ReturnTypeWillChange attribute (PHP 8 >= 8.1.0)
This attribute suggested in the error message didn't even exist until php8.1 yet I and specifying php7.4
So logically, the php version I am doesn't even know this attribute so could not suggest this solution in the error message.
/usr/bin/php7.4 -v
PHP 7.4.33 (cli) (built: Dec 24 2024 07:11:50) ( NTS )
Also odd is that running Artisan command things work fine on 7.4 and error on 8.1
/usr/bin/php7.4 artisan --version
Laravel Framework 6.20.45
/usr/bin/php8.1 artisan --version
PHP Fatal error: During inheritance of ArrayAccess: Uncaught ErrorException: Return type of Illuminate\Support\Collection::offsetExists($key) should either be compatible with ArrayAccess::offsetExists(mixed $of
This confirms that the error is running php7.4 compatible version of Illuminate\Support\Collection on php8.1
But I am running the command in php7.4, so this shouldn't happen!
Have regularly run composer by passing it to a specific php version which always works great, but something seems to be switching php version randomly mid process.
Have tried downgrade to composer2.2 but still same error.
You have multiple versions of PHP installed, and I bet the one on your path as just php will be 8.1 or later. You can confirm this by running which php, or php -v.
Based on the stack trace, this is happening because of the package:discover script, which is registered in the composer file as php artisan package:discover.
Open your composer.json file and try changing @php to /usr/bin/php7.4 and run it again.
Laravel 6 composer file for reference: https://github.com/laravel/laravel/blob/6.x/composer.json