Your requirements could not be resolved to an installable set of packages. Problem 1 - friendsoftypo3/headless is present at version dev-303d59b743b2a85e4c8206ccc06abc17e74bda8f and cannot be modified by Composer - Root composer.json requires phpunit/phpcov ^10 -> satisfiable by phpunit/phpcov[10.0.0]. - Root composer.json requires typo3/cms-install ^12.4 || ^13.4 -> satisfiable by typo3/cms-install[v12.4.0, ..., v12.4.22, v13.4.0]. - Root composer.json requires typo3/minimal ^12 -> satisfiable by typo3/minimal[v12.0.0, v12.4.0]. - phpunit/php-code-coverage 11.0.5 requires nikic/php-parser ^5.0 -> satisfiable by nikic/php-parser[v5.0.0, ..., v5.3.1]. - phpunit/php-code-coverage 11.0.6 requires nikic/php-parser ^5.1.0 -> satisfiable by nikic/php-parser[v5.1.0, v5.2.0, v5.3.0, v5.3.1]. - phpunit/php-code-coverage 11.0.7 requires nikic/php-parser ^5.3.1 -> satisfiable by nikic/php-parser[v5.3.1]. - phpunit/phpcov 10.0.0 requires phpunit/php-code-coverage ^11.0 -> satisfiable by phpunit/php-code-coverage[11.0.0, ..., 11.0.7]. - Conclusion: don't install nikic/php-parser v5.3.1 (conflict analysis result)