'wp fixtures load' failure

[peoyli]

Ubuntu 24.04.1 LTS server (nothing special)
PHP 8.3
User 'ubuntu' is a member of www-data group, site content has group write permissions, wp-config.php is readable by user (no warning/error by executing 'wp-cli').
Installed per the instructions (so Python stuff lands in '/home/ubuntu/.wp-cli/packages/')

No "php-psr" package installed. This was the closest I could find about similar errors.
'composer' not installed (which will also install 'php-psr')
I have tried with the same result with composer installed.

Loading fixtures... This might take some time depending on images number and connection speed PHP Fatal error: Declaration of Psr\Container\ContainerInterface@anonymous::get(string $id): Symfony\Component\TypeInfo\TypeResolver\TypeResolverInterface must be compatible with Psr\Container\ContainerInterface::get($id) in /home/ubuntu/.wp-cli/packages/vendor/symfony/type-info/TypeResolver/TypeResolver.php on line 98 Fatal error: Declaration of Psr\Container\ContainerInterface@anonymous::get(string $id): Symfony\Component\TypeInfo\TypeResolver\TypeResolverInterface must be compatible with Psr\Container\ContainerInterface::get($id) in /home/ubuntu/.wp-cli/packages/vendor/symfony/type-info/TypeResolver/TypeResolver.php on line 98 Error: There has been a critical error on this website.Learn more about troubleshooting WordPress. There has been a critical error on this website.