Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires psalm/plugin-phpunit ^0.19.0 -> satisfiable by psalm/plugin-phpunit[0.19.0]. - Conclusion: don't install sebastian/complexity 4.0.1 (conflict analysis result) - Conclusion: don't install one of phpunit/php-code-coverage[11.0.5], vimeo/psalm[5.26.1] | install nikic/php-parser[v4.17.0] (conflict analysis result) - vimeo/psalm 5.26.1 conflicts with nikic/php-parser v4.17.0. - psalm/plugin-phpunit 0.19.0 requires vimeo/psalm dev-master || ^5@beta || ^5.0 -> satisfiable by vimeo/psalm[5.26.0, 5.26.1]. - Conclusion: don't install vimeo/psalm 5.26.0 (conflict analysis result) - Conclusion: don't install phpunit/phpunit 11.0.0 (conflict analysis result) - phpunit/phpunit 11.4.2 requires phpunit/php-code-coverage ^11.0.7 -> satisfiable by phpunit/php-code-coverage[11.0.7]. - phpunit/phpunit[11.3.2, ..., 11.4.1] require phpunit/php-code-coverage ^11.0.6 -> satisfiable by phpunit/php-code-coverage[11.0.6, 11.0.7]. - phpunit/phpunit[11.2.7, ..., 11.3.1] require phpunit/php-code-coverage ^11.0.5 -> satisfiable by phpunit/php-code-coverage[11.0.5, 11.0.6, 11.0.7]. - phpunit/php-code-coverage[11.0.6, ..., 11.0.7] require sebastian/complexity ^4.0.1 -> satisfiable by sebastian/complexity[4.0.1]. - Conclusion: don't install phpunit/phpunit[11.2.3] | install sebastian/complexity[4.0.1] (conflict analysis result) - Root composer.json requires phpunit/phpunit ^11.0.0 -> satisfiable by phpunit/phpunit[11.0.0, ..., 11.4.2]. Use the option --with-all-dependencies (-W) to allow upgrades, downgrades and removals for packages currently locked to specific versions.