Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires psalm/plugin-phpunit ^0.18.4 -> satisfiable by psalm/plugin-phpunit[0.18.4]. - Conclusion: don't install nikic/php-parser v4.16.0 (conflict analysis result) - Conclusion: don't install vimeo/psalm 5.15.0 (conflict analysis result) - Root composer.json requires vimeo/psalm ^5.15 -> satisfiable by vimeo/psalm[5.15.0, ..., 5.25.0]. - Root composer.json requires phpunit/phpunit ^11.0.0 -> satisfiable by phpunit/phpunit[11.0.0, ..., 11.3.2]. - vimeo/psalm 5.21.1 requires nikic/php-parser ^4.16 -> satisfiable by nikic/php-parser[v4.16.0, ..., v4.19.1]. - vimeo/psalm 5.21.1 conflicts with nikic/php-parser v4.17.0. - psalm/plugin-phpunit 0.18.4 requires vimeo/psalm dev-master || dev-4.x || ^4.7.1 || ^5@beta || ^5.0 -> satisfiable by vimeo/psalm[5.15.0, ..., 5.25.0]. - Conclusion: don't install vimeo/psalm[5.22.0] | install one of nikic/php-parser[v4.16.0, v4.19.0] (conflict analysis result) - Conclusion: don't install vimeo/psalm[5.16.0] | install one of nikic/php-parser[v4.16.0, v4.19.0] (conflict analysis result) - Conclusion: don't install vimeo/psalm[5.22.1] | install one of nikic/php-parser[v4.16.0, v4.19.0] (conflict analysis result) - Conclusion: don't install vimeo/psalm[5.17.0] | install one of nikic/php-parser[v4.16.0, v4.19.0] (conflict analysis result) - Conclusion: don't install vimeo/psalm[5.22.2] | install one of nikic/php-parser[v4.16.0, v4.19.0] (conflict analysis result) - Conclusion: don't install vimeo/psalm[5.18.0] | install one of nikic/php-parser[v4.16.0, v4.19.0] (conflict analysis result) - Conclusion: don't install vimeo/psalm[5.23.0] | install one of nikic/php-parser[v4.16.0, v4.19.0] (conflict analysis result) - Conclusion: don't install vimeo/psalm[5.19.0] | install one of nikic/php-parser[v4.16.0, v4.19.0] (conflict analysis result) - Conclusion: don't install vimeo/psalm[5.23.1] | install one of nikic/php-parser[v4.16.0, v4.19.0] (conflict analysis result) - Conclusion: don't install vimeo/psalm[5.19.1] | install one of nikic/php-parser[v4.16.0, v4.19.0] (conflict analysis result) - Conclusion: don't install vimeo/psalm[5.24.0] | install one of nikic/php-parser[v4.16.0, v4.19.0] (conflict analysis result) - Conclusion: don't install vimeo/psalm[5.20.0] | install one of nikic/php-parser[v4.16.0, v4.19.0] (conflict analysis result) - Conclusion: don't install vimeo/psalm[5.25.0] | install one of nikic/php-parser[v4.16.0, v4.19.0] (conflict analysis result) - Conclusion: don't install vimeo/psalm[5.21.0] | install one of nikic/php-parser[v4.16.0, v4.19.0] (conflict analysis result) - Conclusion: don't install nikic/php-parser v4.19.0 (conflict analysis result) Use the option --with-all-dependencies (-W) to allow upgrades, downgrades and removals for packages currently locked to specific versions.