Your requirements could not be resolved to an installable set of packages. Problem 1 - drupal/devel[1.0.0-alpha1, ..., 1.2.0] require drupal/core ~8.0 -> satisfiable by drupal/core[8.0.0-beta6, ..., 8.9.x-dev] from composer repo (https://repo.packagist.org) but drupal/core[11.0.x-dev] from path repo (core) has higher repository priority. The packages from the higher priority repository do not match your constraint and are therefore not installable. That repository is canonical so the lower priority repo's packages are not installable. See https://getcomposer.org/repoprio for details and assistance. - drupal/devel[dev-1.x, 1.x-dev, 2.0.0] require symfony/var-dumper ~2.7|^3 -> found symfony/var-dumper[v2.7.0, ..., v2.8.52, v3.0.0, ..., v3.4.47] but it conflicts with your root composer.json require (^7.1@RC). - drupal/devel[dev-2.x, 2.1.0, ..., 2.x-dev, 3.0.0-beta1] require symfony/var-dumper ~2.7|^3|^4 -> found symfony/var-dumper[v2.7.0, ..., v2.8.52, v3.0.0, ..., v3.4.47, v4.0.0-RC1, ..., v4.4.47] but it conflicts with your root composer.json require (^7.1@RC). - drupal/devel[dev-3.x, dev-4.x, 3.x-dev, 4.0.0-rc1, ..., 4.x-dev] require drupal/core ^8.8 || ^9 -> satisfiable by drupal/core[8.8.0-alpha1, ..., 8.9.x-dev, 9.0.0-alpha1, ..., 9.5.x-dev] from composer repo (https://repo.packagist.org) but drupal/core[11.0.x-dev] from path repo (core) has higher repository priority. The packages from the higher priority repository do not match your constraint and are therefore not installable. That repository is canonical so the lower priority repo's packages are not installable. See https://getcomposer.org/repoprio for details and assistance. - drupal/devel[5.0.0-beta1, ..., 5.1.2] require drupal/core ^9 || ^10 -> satisfiable by drupal/core[9.0.0-alpha1, ..., 9.5.x-dev, 10.0.0-alpha1, ..., 10.4.x-dev] from composer repo (https://repo.packagist.org) but drupal/core[11.0.x-dev] from path repo (core) has higher repository priority. The packages from the higher priority repository do not match your constraint and are therefore not installable. That repository is canonical so the lower priority repo's packages are not installable. See https://getcomposer.org/repoprio for details and assistance. - drupal/devel[dev-5.x, 5.2.0, ..., 5.x-dev] require symfony/var-dumper ^4 || ^5 || ^6 -> found symfony/var-dumper[v4.0.0-RC1, ..., v4.4.47, v5.0.0-RC1, ..., v5.4.39, v6.0.0-RC1, ..., v6.4.7] but it conflicts with your root composer.json require (^7.1@RC). - Root composer.json requires drupal/devel * -> satisfiable by drupal/devel[dev-1.x, dev-2.x, dev-3.x, dev-4.x, dev-5.x, 1.0.0-alpha1, ..., 1.x-dev, 2.0.0, 2.1.0, 2.x-dev, 3.0.0-beta1, 3.x-dev, 4.0.0-rc1, ..., 4.x-dev, 5.0.0-beta1, ..., 5.x-dev]. Use the option --with-all-dependencies (-W) to allow upgrades, downgrades and removals for packages currently locked to specific versions.