Your requirements could not be resolved to an installable set of packages. Problem 1 - sebastian/diff[3.0.0, ..., 3.0.2] require php ^7.1 -> your php version (8.3.12) does not satisfy that requirement. - sebastian/diff[4.0.0, ..., 4.0.1] require php ^7.3 -> your php version (8.3.12) does not satisfy that requirement. - Root composer.json requires infection/infection 0.29.7 -> satisfiable by infection/infection[0.29.7]. - vimeo/psalm 4.30.0 requires sebastian/diff ^3.0 || ^4.0 -> satisfiable by sebastian/diff[3.0.0, ..., 3.0.6, 4.0.0, ..., 4.0.6]. - You can only install one version of a package, so only one of these can be installed: sebastian/diff[3.0.0, ..., 3.0.6, 4.0.0, ..., 4.0.6, 5.0.0, ..., 5.1.1, 6.0.0, 6.0.1, 6.0.2]. - phpunit/phpunit 10.5.38 requires sebastian/diff ^5.1.1 -> satisfiable by sebastian/diff[5.1.1]. - infection/infection 0.29.7 requires infection/mutator ^0.4 -> satisfiable by infection/mutator[0.4.0]. - Root composer.json requires phpunit/phpunit ^10.5.38 -> satisfiable by phpunit/phpunit[10.5.38]. - Conclusion: don't install vimeo/psalm 5.15.0 (conflict analysis result) - vimeo/psalm[5.26.0, ..., 5.26.1] require nikic/php-parser ^4.17 -> satisfiable by nikic/php-parser[v4.17.0, ..., v4.19.4]. - vimeo/psalm[5.16.0, ..., 5.25.0] require nikic/php-parser ^4.16 -> satisfiable by nikic/php-parser[v4.16.0, ..., v4.19.4]. - You can only install one version of a package, so only one of these can be installed: nikic/php-parser[v4.13.0, ..., v4.19.4, v5.0.0, ..., v5.3.1]. - infection/mutator 0.4.0 requires nikic/php-parser ^5.0 -> satisfiable by nikic/php-parser[v5.0.0, ..., v5.3.1]. - Conclusion: don't install nikic/php-parser v5.0.0 (conflict analysis result) - Root composer.json requires vimeo/psalm ^4.30.0 || ^5.15 -> satisfiable by vimeo/psalm[4.30.0, 5.15.0, ..., 5.26.1]. Use the option --with-all-dependencies (-W) to allow upgrades, downgrades and removals for packages currently locked to specific versions.