Your requirements could not be resolved to an installable set of packages. Problem 1 - drush/drush[12.4.3, ..., 12.x-dev] require symfony/yaml ^6.0 -> satisfiable by symfony/yaml[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/yaml[2.0.5, ..., 2.8.x-dev, v3.0.0-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, ..., 7.1.x-dev]. - drupal/core 11.x-dev requires symfony/yaml ^7.0 -> satisfiable by symfony/yaml[v7.0.0-BETA1, ..., 7.1.x-dev]. - drupal/core 11.x-dev conflicts with drush/drush 12.4.2. - drupal/core 11.x-dev conflicts with drush/drush 12.1.1. - drupal/core 11.x-dev conflicts with drush/drush 12.0.0-rc2. - drupal/core 11.x-dev conflicts with drush/drush 12.0.0-beta1. - drupal/core 11.x-dev conflicts with drush/drush 11.6.0. - drupal/core 11.x-dev conflicts with drush/drush 11.5.1. - drupal/core 11.x-dev conflicts with drush/drush 11.3.2. - drupal/core 11.x-dev conflicts with drush/drush 11.3.1. - drupal/core 11.x-dev conflicts with drush/drush 11.2.1. - drupal/core 11.x-dev conflicts with drush/drush 11.1.1. - drupal/core 11.x-dev conflicts with drush/drush 11.0.9. - drupal/core 11.x-dev conflicts with drush/drush 11.0.7. - drupal/core 11.x-dev conflicts with drush/drush 11.0.5. - drupal/core 11.x-dev conflicts with drush/drush 11.0.1. - drupal/core 11.x-dev conflicts with drush/drush 11.0.0-rc7. - drupal/core 11.x-dev conflicts with drush/drush 11.0.0-rc5. - drupal/core 11.x-dev conflicts with drush/drush 11.0.0-rc3. - drupal/core 11.x-dev conflicts with drush/drush 11.0.0-rc2. - drupal/core 11.x-dev conflicts with drush/drush 11.0.0-rc1. - Root composer.json requires drupal/core * -> satisfiable by drupal/core[11.x-dev]. - Root composer.json requires drush/drush ^11 || ^12 -> satisfiable by drush/drush[11.0.0-rc1, ..., 11.x-dev, 12.0.0-beta1, ..., 12.x-dev].