Your requirements could not be resolved to an installable set of packages. Problem 1 - drupal/core-dev[11.0.0-beta1, ..., 11.x-dev] require phpunit/phpunit ^10.5.19 -> found phpunit/phpunit[10.5.19, ..., 10.5.x-dev] but it conflicts with your root composer.json require (^9.5). - Root composer.json requires drupal/helfi_drupal_tools dev-main -> satisfiable by drupal/helfi_drupal_tools[dev-main]. - drupal/helfi_drupal_tools dev-main requires drush/drush ^11 || ^12 || ^13 -> satisfiable by drush/drush[12.0.0-beta1, ..., 12.x-dev]. - drush/drush[12.0.0-beta1, ..., 12.x-dev] require symfony/var-dumper ^6.0 -> satisfiable by symfony/var-dumper[v6.0.0-BETA1, ..., 6.4.x-dev]. - You can only install one version of a package, so only one of these can be installed: symfony/var-dumper[v3.4.0-BETA1, ..., 3.4.x-dev, v4.0.0-BETA1, ..., 4.4.x-dev, v5.0.0-BETA1, ..., 5.4.x-dev, v6.0.0-BETA1, ..., 6.4.x-dev, v7.0.0-BETA1, ..., 7.2.x-dev]. - drupal/core-dev 11.0.0-alpha1 requires symfony/var-dumper ^7.0 -> satisfiable by symfony/var-dumper[v7.0.0-BETA1, ..., 7.2.x-dev]. - Root composer.json requires drupal/core-dev ^11 -> satisfiable by drupal/core-dev[11.0.0-alpha1, ..., 11.x-dev].